View source for 23 (number)

{{Infobox number
| number =  23
| factorization = [[Prime number|prime]]
| numeral = trivigesimal
| prime = 9th
| divisor = 1, 23
}}

'''23''' ('''twenty-three''') is the [[Natural number|natural number]] following [[22 (number)|22]] and preceding [[24 (number)|24]].

== In mathematics ==
'''Twenty-three''' is the ninth [[Prime number|prime number]], the smallest odd prime that is not a [[Twin prime|twin prime]].<ref>{{Cite OEIS |A007510 |Single (or isolated or non-twin) primes: Primes p such that neither p-2 nor p+2 is prime. |access-date=2022-12-05 }}</ref> It is, however, a [[Cousin prime|cousin prime]] with [[19 (number)|19]], and a [[Sexy prime|sexy prime]] with [[17 (number)|17]] and [[29 (number)|29]]; while also being the largest member of the first [[Prime quadruplet#Prime sextuplets|prime sextuplet]] ([[7|7]], [[11 (number)|11]], [[13 (number)|13]], 17, 19, 23).<ref>{{Cite OEIS |A001223 |Prime gaps: differences between consecutive primes. |access-date=2023-06-11 }}</ref> Twenty-three is also the fifth [[Factorial prime|factorial prime]],<ref>{{Cite OEIS|1=A088054|2=Factorial primes|access-date=2016-05-31}}</ref> the second [[Woodall prime]],<ref>{{Cite OEIS|1=A050918|2=Woodall primes|access-date=2016-05-31}}</ref> and a [[Happy number|happy number]] in decimal.<ref>{{Cite OEIS|1=A007770|2=Happy numbers|access-date=2016-05-31}}</ref> It is an [[Eisenstein prime]] with no imaginary part and real part of the form <math>3n-1.</math> It is also the fifth Sophie Germain prime<ref>{{Cite OEIS|1=A005384|2=Sophie Germain primes|access-date=2016-05-31}}</ref> and the fourth [[Safe prime|safe prime]],<ref>{{Cite OEIS|1=A005385|2=Safe primes|access-date=2016-05-31}}</ref> and the next to last member of the first [[Cunningham chain]] of the first kind to have five terms ([[2|2]], [[5|5]], 11, 23, [[47 (number)|47]]).<ref>{{Cite OEIS |A192580 |Monotonic ordering of set S generated by these rules: if x and y are in S and xy+1 is a prime, then xy+1 is in S, and 2 is in S. |access-date=2023-06-11 }}
:"'''2, 5, 11, 23, 47''' is the complete Cunningham chain that begins with 2. Each term except the last is a Sophie Germain prime A005384."</ref> Since 14[[Factorial|!]] + 1 is a multiple of 23, but 23 is not one more than a multiple of [[14 (number)|14]], 23 is the first [[Pillai prime]].<ref>{{Cite OEIS|1=A063980|2=Pillai primes|access-date=2016-05-31}}</ref> 23 is the smallest odd prime to be a [[Highly cototient number|highly cototient number]], as the solution to <math>x-\phi(x)</math> for the integers [[95 (number)|95]], [[119 (number)|119]], [[143 (number)|143]], and 529.<ref>{{Cite OEIS|1=A100827|2=Highly cototient numbers|access-date=2016-05-31}}</ref>

* 23 is the second Smarandache–Wellin prime in [[Radix|base]] ten, as it is the concatenation of the decimal representations of the first two primes (2 and 3) and is itself also prime.<ref>{{Cite OEIS|1=A069151|2=Concatenations of consecutive primes, starting with 2, that are also prime|access-date=2016-05-31}}</ref>

* The sum of the first nine primes up to 23 is a [[Square number|square]]: <math>2 + 3 + \dots + 23 = 100 = 10^{2}</math> and the sum of the first 23 primes is 874, which is divisible by 23, a property shared by few other numbers.<ref>{{OEIS|id=A045345}}</ref><ref>{{Cite web|title=Puzzle 31.- The Average Prime number, APN(k) {{=}} S(Pk)/k|url=https://www.primepuzzles.net/puzzles/puzz_031.htm|access-date=2022-11-29|website=www.primepuzzles.net}}</ref>

* In the list of [[Fortunate number|fortunate number]]s, 23 occurs twice, since adding 23 to either the fifth or eighth [[Primorial|primorial]] gives a prime number (namely 2333 and 9699713).<ref>{{Cite OEIS|1=A005235|2=Fortunate numbers|access-date=2016-05-31}}</ref>

* 23 has the distinction of being one of two integers that cannot be expressed as the sum of fewer than 9 cubes of positive integers (the other is [[239 (number)|239]]). See [[Waring's problem]].

*The twenty-third [[Highly composite number|highly composite number]] 20,160<ref>{{Cite OEIS |A002182 |Highly composite numbers, definition (1): numbers n where d(n), the number of divisors of n (A000005), increases to a record. |access-date=2023-10-09 }}</ref> is one less than the last number (the 339th [[Super-prime|super-prime]] 20,161) that cannot be expressed as the sum of two [[Abundant number|abundant number]]s.<ref>{{Cite OEIS |A048242 |Numbers that are not the sum of two abundant numbers (not necessarily distinct). |access-date=2023-10-09 }}</ref>
:Otherwise, <math>46 = 23 \times 2</math> is the largest [[Parity (mathematics)|even]] number that is not the sum of two abundant numbers.

* 23 is the number of [[Tree (graph theory)|trees]] on 8 unlabeled nodes.<ref>{{Cite web|title=Sloane's A000055: Number of trees with n unlabeled nodes|url=https://oeis.org/A000055|url-status=live|access-date=2021-12-19|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|archive-url=https://web.archive.org/web/20101129012954/http://oeis.org:80/A000055 |archive-date=29 November 2010 }}</ref> It is also a [[Wedderburn–Etherington number]], which are numbers that can be used to count certain binary trees.<ref>{{Cite OEIS|1=A001190|2=Wedderburn-Etherington numbers|access-date=2016-05-31}}</ref>

* The [[Natural logarithm|natural logarithm]]s of all positive integers lower than 23 are known to have binary BBP-type formulae.<ref>{{Cite web |last1=Chamberland |first1=Marc |title=Binary BBP-Formulae for Logarithms and Generalized Gaussian-Mersenne Primes |url=https://chamberland.math.grinnell.edu/papers/bbp.pdf}}</ref>

* 23 is the first prime ''p'' for which unique factorization of [[Cyclotomic field|cyclotomic integers]] based on the ''p''th root of unity breaks down.<ref>{{Cite web|url=http://mathworld.wolfram.com/CyclotomicInteger.html|title=Cyclotomic Integer|last=Weisstein|first=Eric W.|website=mathworld.wolfram.com|language=en|access-date=2019-01-15}}</ref>

* 23 is the smallest positive solution to Sunzi's original formulation of the [[Chinese remainder theorem]].

* 23 is the smallest [[Prime number|prime]] <math>p</math> such that the largest consecutive pair of <math>p-</math>smooth numbers (11859210, 11859211) is the same as the largest consecutive pair of <math>(p-1)-</math>smooth numbers.<ref>{{Cite OEIS |A228611 |Primes p such that the largest consecutive pair of <math>p</math> -smooth integers is the same as the largest consecutive pair of <math>p-1</math>-smooth integers |access-date=2016-05-31 }}</ref>

* According to the birthday paradox, in a group of 23 or more randomly chosen people, the probability is more than 50% that some pair of them will have the same birthday.<ref>{{Cite web|last=Weisstein|first=Eric W.|title=Birthday Problem|url=https://mathworld.wolfram.com/BirthdayProblem.html|access-date=2020-08-19|website=mathworld.wolfram.com|language=en}}</ref>
:A related coincidence is that [[365 (number)|365]] times the [[Natural logarithm|natural logarithm]] of 2, approximately 252.999, is very close to the number of pairs of 23 items and 22nd [[Triangular number|triangular number]], [[253 (number)|253]].  

* The first twenty-three odd prime numbers (between [[3|3]] and [[89 (number)|89]] inclusive), are all [[Cluster prime|cluster prime]]s <math>p</math> such that every even positive integer <math>k \le p - 3</math> can be written as the sum of two prime numbers that do not exceed <math>p</math>.<ref>{{Cite OEIS |A038133 |From a subtractive Goldbach conjecture: odd primes that are not cluster primes. |access-date=2022-12-26 }}</ref>

* The twenty-third [[Permutable prime|permutable prime]] in decimal <math>R_{19}</math> is also the second to be a [[Repunit#Repunit primes|prime repunit]] (after <math>R_{2}</math>), followed by <math>R_{23}</math> and <math>R_{1031}</math>.<ref>Guy, Richard; ''Unsolved Problems in Number Theory'', p. 7 {{ISBN|1475717385}}</ref><ref>{{Cite OEIS |A003459 |Absolute primes (or permutable primes): every permutation of the digits is a prime. |access-date=2024-01-10}}</ref><ref>{{Cite OEIS |A004022 |Primes of the form (10^k - 1)/9. Also called repunit primes or repdigit primes. |access-date=2024-01-10 }}</ref><ref>{{Cite OEIS |A004023 |Indices of prime repunits: numbers n such that 11...111 (with n 1's) equal to (10^n - 1)/9 is prime. |access-date=2024-01-10 }}</ref>

=== Mersenne numbers ===

The first Mersenne number of the form <math>2^{n} - 1</math> that does not yield a [[Prime number|prime number]] when inputting a prime exponent is <math> 2047 = 23 \times 89,</math> with <math>n=11.</math><ref>{{Cite OEIS |A000225 |Mersenne numbers |access-date=2023-02-16 }}</ref> 

On the other hand, the second [[Composite number|composite]] Mersenne number contains an exponent <math>n</math> of twenty-three: 

<math display=block>M_{23} = 2^{23} - 1 = 8\;388\;607 = 47 \times 178\;481</math>

The twenty-third prime number ([[83 (number)|83]]) is an exponent to the fourteenth composite Mersenne number, which factorizes into two prime numbers, the largest of which is twenty-three digits long when written in base ten:<ref>{{Cite OEIS |A136030 |Smallest prime factor of composite Mersenne numbers. |access-date=2023-06-12 }}</ref><ref>{{Cite OEIS |A136031 |	Largest prime factor of composite Mersenne numbers. |access-date=2023-06-12 }}</ref>

<math display=block>M_{83} = 967...407 = 167 \times 57\;912\;614\;113\;275\;649\;087\;721</math>

Further down in this sequence, the seventeenth and eighteenth composite Mersenne numbers have two prime factors each as well, where the largest of these are respectively twenty-two and twenty-four digits long,

<math display=block>
\begin{align}
M_{103} & = 101 \ldots 007 = 2\;550\;183\;799 \times 3\;976\;656\;429\;941\;438\;590\;393 \\
M_{109} & = 649 \ldots 511 = 745\;988\;807 \times 870\;035\;986\;098\;720\;987\;332\;873 \\
\end{align}
</math>

Where prime exponents for <math>M_{23}</math> and <math>M_{83}</math> add to [[106 (number)|106]], which lies in between prime exponents of <math>M_{103}</math> and <math>M_{109}</math>, the index of the latter two ([[17 (number)|17]] and [[18 (number)|18]]) in the sequence of Mersenne numbers sum to [[35 (number)|35]], which is the twenty-third composite number.<ref>{{Cite OEIS |A002808 |The composite numbers: numbers n of the form x*y for x > 1 and y > 1. |access-date=2024-01-09 }}</ref>

<math>23!</math> is twenty-three [[Numerical digit|digits]] long in decimal, and there are only three other numbers <math>n</math> whose [[Factorial|factorial]]s generate numbers that are <math>n</math> digits long in base ten: [[1|1]], [[22 (number)|22]], and&nbsp;[[24 (number)|24]].

=== In geometry ===

The '''[[Leech lattice]]''' '''Λ<sub>24</sub>''' is a 24-dimensional [[Lattice (group)|lattice]] through which 23 other positive definite even [[Unimodular lattice|unimodular]] [[Niemeier lattice]]s of [[Rank of an abelian group|rank]] 24 are built, and vice-versa. '''Λ<sub>24</sub>''' represents the solution to the [[Kissing number|kissing number]] in 24 dimensions as the precise lattice structure for the maximum number of [[Sphere|sphere]]s that can fill 24-dimensional space without overlapping, equal to 196,560 spheres. These 23 Niemeier lattices are located at ''deep holes'' of [[Radius|radii]] {{math|{{sqrt|2}}}} in lattice points around its automorphism group, [[Conway group]] <math>\mathbb C_{0}</math>. The Leech lattice can be constructed in various ways, which include:

* By means of a [[Matrix (mathematics)|matrix]] of the form <math>\scriptstyle\begin{pmatrix} Ia&H/2\\H/2&Ib\end{pmatrix}</math> where <math>I</math> is the [[Identity matrix|identity matrix]] and <math>H</math> is a 24 by 24 [[Hadamard matrix]] ('''Z'''/23'''Z''' ∪ ∞) with ''a'' = 2 and ''b'' = 3, and [[Matrix (mathematics)#Definition|entries]] X(∞) = 1 and X(0) = -1 with X(''n'') the [[Quadratic residue|quadratic residue]] symbol [[Modulo operation|mod]] 23 for nonzero ''n''.

* Through the extended binary Golay code <math>\mathbb B_{24}</math> and [[Steiner system#The Steiner system S(5, 8, 24)|Witt design <math>\mathbb W {24}</math>]], which produce a construction of the 196,560 minimal [[Row and column vectors|vectors]] in the Leech lattice. The extended binary Golay code is an extension of the perfect [[Binary Golay code|binary Golay code]] <math>\mathbb B_{23}</math>, which has [[Code word (communication)|codeword]]s of [[Block code#The alphabet Σ|size]]&nbsp;23. <math>\mathbb B_{23}</math> has [[Mathieu group M23|Mathieu group <math>\mathbb M {23}</math>]] as its automorphism group, which is the second largest member of the [[Sporadic group#Happy Family|first generation]] in the [[Sporadic group#Happy Family|happy family]] of sporadic groups. <math>\mathbb M_{23}</math> has a minimum [[Faithful representation|faithful complex representation]] in 22 [[Physics:Dimension|dimension]]s and [[Group action|group-3 actions]] on [[253 (number)|253]] [[Group object|objects]], with 253 equal to the number of pairs of objects in a set of 23 objects. In turn, <math>\mathbb M_{23}</math> is the automorphism group of [[Mathieu group M24|Mathieu group <math>\mathbb M {24}</math>]], which works through <math>\mathbb W_{24}</math> to generate '''8'''-element ''octads'' whose individual elements occur 253 times through its entire [[Block design|block design]].

* Using Niemer lattice '''D'''<sub>24</sub> of group order 2<sup>23</sup>·24! and Coxeter number 46 = 2·23, it can be made into a [[Module (mathematics)|module]] over the [[Ring of integers|ring of integers]] of [[Quadratic field|quadratic field]] <math>\mathbb{Q}(\sqrt{-23})</math>, whereby multiplying '''D'''<sub>24</sub> by a [[Principal ideal#Examples of non-principle ideals|non-principal ideal]] of the ring of integers yields the Leech lattice. 

Conway and [[Biography:Neil Sloane|Sloane]] provided constructions of the Leech lattice from all other 23 Niemeier lattices.<ref>{{Cite journal| last1=Conway | first1=John Horton |  last2=Sloane | first2=N. J. A. |  title=Twenty-three constructions for the Leech lattice | doi=10.1098/rspa.1982.0071 | mr=661720 | year=1982 | journal=Proceedings of the Royal Society A | issn=0080-4630 | volume=381 | issue=1781 | pages=275–283| bibcode=1982RSPSA.381..275C | s2cid=202575295 }}</ref>

Twenty-three four-dimensional [[Crystal system#Crystal family|crystal families]] exist within the classification of [[Space group#In other dimensions|space groups]]. These are accompanied by six [[Chirality (mathematics)|enantiomorphic]] forms, maximizing the total count to [[29 (number)|twenty-nine]] crystal families.<ref>{{Cite OEIS |A004032 |Number of n-dimensional crystal families. |access-date=2022-11-21 }}</ref> Five [[Cube|cube]]s can be arranged to form twenty-three [[Polycube#Enumerating polycubes|free pentacubes]], or twenty-nine distinct ''one-sided'' pentacubes (with reflections).<ref>{{Cite OEIS |A000162 |Number of three dimensional polyominoes (or polycubes) with n cells. |access-date=2023-01-06 }}</ref><ref>{{Cite OEIS |A038119 |Number of n-celled solid polyominoes (or free polycubes, allowing mirror-image identification) }}</ref>

There are 23 three-dimensional [[Uniform polyhedron|uniform polyhedra]] that are [[Facet (geometry)|cell facets]] inside uniform 4-polytopes that are not part of infinite families of [[Uniform antiprismatic prism|antiprismatic prisms]] and duoprisms: the five [[Platonic solid]]s, the thirteen [[Archimedean solid]]s, and five semiregular [[Prism (geometry)|prisms]] (the [[Triangular prism|triangular]], [[Pentagonal prism|pentagonal]], [[Hexagonal prism|hexagonal]], [[Octagonal prism|octagonal]], and [[Decagonal prism|decagonal]] prisms).

23 [[Coxeter group]]s of paracompact hyperbolic honeycombs in the [[Three-dimensional space|third dimension]] generate [[151 (number)|151]] unique [[Wythoff construction|Wythoffian]] constructions of paracompact honeycombs. 23 four-dimensional Euclidean honeycombs are generated from the [[Uniform 5-polytope#Regular and uniform honeycombs|<math>{\tilde{B}} 4</math> cubic group]], and 23 five-dimensional [[Uniform 5-polytope#Enumerating the convex uniform 5-polytopes|uniform polytopes]] are generated from the [[D5 polytope|<math>\mathrm D {5}</math> demihypercubic group]].

In [[Plane (geometry)|two-dimensional]] geometry, the regular 23-sided icositrigon is the first regular polygon that is not constructible with a [[Constructible polygon#Compass and straightedge constructions|compass and straight edge]] or with the aide of an [[Angle trisection|angle trisector]] (since it is neither a Fermat prime nor a [[Pierpont prime]]), nor by [[Neusis construction|neusis]] or a double-notched straight edge.<ref>Arthur Baragar (2002) Constructions Using a Compass and Twice-Notched Straightedge, The American Mathematical Monthly, 109:2, 151-164, {{doi|10.1080/00029890.2002.11919848}}</ref> It is also not constructible with origami, however it is through other traditional methods for all regular polygons.<ref>P. Milici, R. Dawson ''The equiangular compass'' December 1st, 2012, The Mathematical Intelligencer, Vol. 34, Issue 4 https://www.researchgate.net/profile/Pietro_Milici2/publication/257393577_The_Equiangular_Compass/links/5d4c687da6fdcc370a8725e0/The-Equiangular-Compass.pdf</ref>

==In science and technology==
* The [[Physics:Atomic number|atomic number]] of [[Chemistry:Vanadium|vanadium]].
* The atomic mass number of the [[Physics:Stable isotope|stable isotope]] of [[Chemistry:Sodium|sodium]].
* Normal human sex cells have 23 [[Biology:Chromosome|chromosome]]s.<ref>H. Wramsby, K. Fredga, P. Liedholm, "Chromosome analysis of human oocytes recovered from preovulatory follicles in stimulated cycles" ''New England Journal of Medicine'' '''316''' 3 (1987): 121 – 124</ref> Other human cells have 46 chromosomes, arranged in 23 pairs.<ref>Barbara J. Trask, "Human genetics and disease: Human cytogenetics: 46 chromosomes, 46 years and counting" ''Nature Reviews Genetics'' '''3''' (2002): 769. "Human cytogenetics was born in 1956 with the fundamental, but empowering, discovery that normal human cells contain 46 chromosomes."</ref>
* Scientific notation for the [[Physics:Avogadro constant|Avogadro constant]] is written as {{physconst|NA|unit=no|ref=no}}.<ref name="SI2019">{{Cite book
 | last1 = Newell
 | first1 = David B.
 | last2 = Tiesinga
 | first2 = Eite
 | year = 2019
 | title = The International System of Units (SI)
 | series = NIST Special Publication 330
 | publisher = National Institute of Standards and Technology
 | location = Gaithersburg, Maryland
 | url = https://www.nist.gov/si-redefinition/meet-constants
 | doi = 10.6028/nist.sp.330-2019
| s2cid = 242934226
 }}</ref>
* 23 is the width of the [[Astronomy:Arecibo message|Arecibo message]], sent to space in search for extraterrestrial intelligence.
* 23 is the TCP/IP port used for [[Telnet|telnet]] and is the default for the telnet command.<ref>{{IETF RFC|854}}, Telnet Protocol Specification</ref>
* The [[Astronomy:Earth#Axial tilt and seasons|earth's axis]] is tilted at approximately 23°.

==In religion==
* In [[Unsolved:Biblical numerology|Biblical numerology]], it is associated with Psalm 23, also known as the Shepherd Psalm. It is possibly the most quoted and best known Psalm.<ref>{{Cite web|title="The Lord is My Shepherd, I Shall Not Want" – Meaning of Psalm 23 Explained|url=https://www.christianity.com/wiki/bible/the-lord-is-my-shepherd-in-psalm-23.html|access-date=2021-06-07|website=Christianity.com|language=en}}</ref><ref>Miriam Dunson, ''A Very Present Help: Psalm Studies for Older Adults''. New York: Geneva Press (1999): 91. "Psalm 23 is perhaps the most familiar, the most loved, the most memorized, and the most quoted of all the psalms."</ref> Psalms is also the 23rd book in the Douay–Rheims Bible.
* In Islam, the Qur'an was revealed in a total of 23 years to Muhammed.<ref>''Living Religions: An Encyclopaedia of the World's Faiths,'' Mary Pat Fisher, 1997, page 338, I.B. Tauris Publishers,</ref><ref>Qur'an, Chapter 17, Verse 106</ref>
* Muslims believe the first verses of the Qur'an were revealed to the Islamic prophet Muhammad on the 23rd night of the 9th Islamic month, though, its disputed. <ref>Quran, Chapter 97</ref> 
* ''[[Religion:Principia Discordia|Principia Discordia]]'', the sacred text of Discordianism, holds that 23 (along with the discordian prime 5) is one of the sacred numbers of [[Astronomy:Eris (mythology)|Eris]], goddess of discord.

==In popular culture==
===Music===
* Alfred Harth uses the number 23 in his artist name Alfred 23 Harth, or A23H, since the year 1+9+8+5 = 23.
* ''Twentythree'' is the name of Tristan Prettyman's debut album
* ''Twentythree'' an album by Carbon Based Lifeforms
*  "''Viginti Tres''" (Latin for twenty-three) is a song by Tool on their album ''10,000 Days''
* Blink-182's song "What's My Age Again?" includes the lyrics "nobody likes you when you're 23."
* ''23'' is an album and title track by Blonde Redhead
* The Incubus song "Pardon Me" includes the lyrics "A decade ago, I never thought I would be, at 23, on the verge of spontaneous combustion, woe is me!" Frontman Brandon Boyd was 23 years old when he wrote the song and described himself as being "kind of obsessive about that number".<ref>{{Cite web |last=Rampton |first=Mike |date=October 19, 2019 |title=A Deep Dive Into Incubus' Pardon Me Video |url=https://www.kerrang.com/a-deep-dive-into-incubus-pardon-me-video |website=kerrang.com}}</ref> 
* "23" is a song by Jimmy Eat World, on their album ''Futures''. The number also appears in the songs "Christmas Card" and "12."23".95" as well as on some items of clothing produced by the band.
* Four tet and Yellowcard both have songs titled "Twenty-Three".
* ''Dear 23'', an album by The Posies
* ''Untitled 23'', an album by The Church
* Noah23 has several albums which reference the number 23, such as ''Neophyte Phenotype'', ''Rock Paper Scissors'', and ''Upside Down Bluejay'', all of which have 23 tracks. His stage name also references the number.
* "23 Minutes in Brussels", a song by Luna on their album ''Penthouse''.
* The composer Alban Berg had a particular interest in the number 23, using it to structure several works.  Various suggestions have been made as to the reason for this interest: that he took it from the Biorhythms theory of Wilhelm Fliess, in which a 23-day cycle is considered significant,<ref>{{Cite journal|jstor = 962034|doi = 10.2307/962034|title = Alban Berg, Wilhelm Fliess and the Secret Programme of the Violin Concerto|year = 1983|last1 = Jarman|first1 = Douglas|journal = The Musical Times|volume = 124|issue = 1682|pages = 218–223}}</ref> or because he first suffered an asthma attack on 23rd of the month.<ref>{{Cite book|last=Jarman|first=Douglas|url=https://books.google.com/books?id=-84UtteI-F0C&pg=PA229|title=The Music of Alban Berg|date=1985|publisher=University of California Press|isbn=978-0-520-04954-3|language=en}}</ref>{{importance inline|date=May 2020}}
*  "23" is a single by Mike Will Made It
* On the cover of The Beatles' 1969 album ''Yellow Submarine'' the number 23 is displayed on the chest of one of the Blue Meanies.
* Network 23 refers to members of the Spiral Tribe. Sometimes 23 used to discretely mark the spots of a freetekno rave.
* The number 23 is used a lot throughout the visuals and music by the band Gorillaz, who have even devoted a whole page of their autobiography ''Rise Of The Ogre'' to the [[Unsolved:23 enigma|23 enigma]] theory.

===Film and television===
* ''23'' is a German film about [[Biography:Karl Koch (hacker)|Karl Koch]].<ref>{{Citation|title=23 (1998) – Hans-Christian Schmid {{!}} Synopsis, Characteristics, Moods, Themes and Related {{!}} AllMovie|url=https://www.allmovie.com/movie/23-v168222|language=en-us|access-date=2020-08-12}}</ref>
* In ''Jeepers Creepers'', the Creeper appears every 23 years for 23 days to feast on human body parts
* In ''L: Change the World'', the protagonist L signs his own name in the ''Death Note'' notebook and somehow knows that he has given himself 23 days to live, revealing a 23-day rule for the maximum number of days a person may live after they are added to the Japanese god of death's Death Note.<ref>{{Citation|title=L: Change the World (2008) – Hideo Nakata {{!}} Synopsis, Characteristics, Moods, Themes and Related {{!}} AllMovie|url=https://www.allmovie.com/movie/l-change-the-world-v433309|language=en-us|access-date=2020-08-12}}</ref>
* The 1980s TV series ''Max Headroom'' was set at Network 23.
* In ''The Big Lebowski'', the main characters deliberately use only lane 23 at the bowling alley.{{Citation needed|date=July 2023}}
* In ''The Matrix Reloaded'', the Architect tells Neo it is of utmost importance to choose 23 people to repopulate Zion.
* In the TV series ''Lost'', 23 is one of the 6 reoccurring numbers (4, 8, 15, 16, 23, 42) that appear frequently throughout the show.
* ''The Number 23'' is a 2007 film starring Jim Carrey about a man who becomes obsessed with the [[Unsolved:23 enigma|23 enigma]].<ref>{{Citation|title=The Number 23 (2007) – Joel Schumacher {{!}} Synopsis, Characteristics, Moods, Themes and Related {{!}} AllMovie|url=https://www.allmovie.com/movie/the-number-23-v336722|language=en-us|access-date=2020-08-12}}</ref>

===Other fields===

* 23 skidoo (phrase) (sometimes 23 skiddoo) is an American slang phrase popularized during the early 20th century. 23 skidoo has been described as "perhaps the first truly national fad expression and one of the most popular fad expressions to appear in the U.S".
* The [[Unsolved:23 enigma|23 enigma]], proposed by [[Biography:William S. Burroughs|William S. Burroughs]] plays a prominent role in the plot of ''[[Religion:The Illuminatus! Trilogy|the Illuminatus! Trilogy]]'' by Robert Shea and [[Biography:Robert Anton Wilson|Robert Anton Wilson]].
* ''The 23'', in {{wipe|South Africa}}, refers to the 23 [[Social:Conscientious objector|conscientious objector]]s who publicly refused to do military service in the Apartheid army in 1987. The following years the number increased to 143 (in 1988) and 771 (in 1989), with Apartheid being dismantled from 1990 onwards.<ref>{{Cite web |title=Nan Cross: Supported men resisting apartheid conscription |url=https://www.pressreader.com/south-africa/sunday-times/20070722/282020437891324 |access-date=2023-03-04 |publisher=Sunday Times |date=22 July 2007 |via=PressReader}}</ref>
* X-23 is a character in the Marvel Universe. She is named for being the 23rd attempt to create a female genetic twin of Wolverine after attempts to create a male clone failed.
* 23 is the number of times Julius Caesar was stabbed in the Theatre of Pompey.

==In sports==
* Each national team competing in the FIFA Women's World Cup is allowed a 23-player squad. This squad size has been in place since 2015.

==References==
{{Reflist|30em}}

==External links==
* [https://web.archive.org/web/20141222234706/http://www.dauddegtre.co.uk/ 23 facts, 23 images, 23 gallery, and links to other 23's]


[[Category:Integers]]

{{Sourceattribution|23 (number)}}