View source for 89 (number)

{{Infobox number
| number = 89
| factorization = [[Prime number|prime]]
| prime = 24th
| divisor = 1, 89
}}
'''89''' ('''eighty-nine''') is the [[Natural number|natural number]] following [[88 (number)|88]] and preceding [[90 (number)|90]].

== In mathematics ==
'''89''' is:

* the 24th [[Prime number|prime number]], following [[83 (number)|83]] and preceding [[97 (number)|97]].
* a [[Chen prime]].<ref>{{Cite web|url=https://oeis.org/A109611|title=Sloane's A109611 : Chen primes|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}</ref>
* a [[Pythagorean prime]].<ref>{{Cite web|url=https://oeis.org/A002144|title=Sloane's A002144 : Pythagorean primes|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}</ref>
* the smallest Sophie Germain prime to start a [[Cunningham chain]] of the first kind of six terms, {89, 179, 359, 719, 1439, 2879}.
* an [[Eisenstein prime]] with no imaginary part and real part of the form {{nowrap|3''n'' − 1}}.
* a [[Fibonacci number]] and thus a [[Fibonacci prime]] as well.<ref>{{Cite web|url=https://oeis.org/A005478|title=Sloane's A005478 : Prime Fibonacci numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}</ref> The first few digits of its reciprocal coincide with the Fibonacci sequence due to the identity 
::<math>\frac{1}{89}=\sum_{n=1}^\infty{F(n)\times 10^{-(n+1)}}=0.011235955\dots\ .</math>
* a [[Markov number]], appearing in solutions to the Markov Diophantine equation with other odd-indexed Fibonacci numbers.

''M''<sub>89</sub> is the 10th [[Mersenne prime]].

Although 89 is not a [[Lychrel number]] in base 10, it is unusual that it takes 24 iterations of the reverse and add process to reach a palindrome. Among the known non-Lychrel numbers in the first 10000 integers, no other number requires that many or more iterations. The palindrome reached is also unusually large: 8813200023188.<ref>Weisstein, Eric W. "196-Algorithm." From MathWorld, a Wolfram Web Resource. [http://mathworld.wolfram.com/196-Algorithm.html http://mathworld.wolfram.com/196-Algorithm.html]</ref>

There are exactly 1000 prime numbers between 1 and 89<sup>2</sup>=7921. <ref>{{Cite web |title=Prime Curios! 89 |url=https://primes.utm.edu/curios/page.php/89.html |access-date=2022-12-19 |website=primes.utm.edu}}</ref>

==In science==
'''Eighty-nine''' is:

* The [[Physics:Atomic number|atomic number]] of [[Chemistry:Actinium|actinium]].

===In astronomy===
*[[Astronomy:Messier object|Messier object]] [[Astronomy:Messier 89|M89]], a magnitude 11.5 [[Astronomy:Elliptical galaxy|elliptical galaxy]] in the [[Astronomy:Constellation|constellation]] [[Astronomy:Virgo (constellation)|Virgo]].<ref name="ned">
{{cite web
 | title=NASA/IPAC Extragalactic Database
 | work=Results for NGC 4552
 | url=http://ned.ipac.caltech.edu/cgi-bin/objsearch?objname=m89&extend=no&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES
 | access-date=2006-10-24
}}</ref>
*The [[Astronomy:New General Catalogue|New General Catalogue]] object [[Astronomy:NGC 89|NGC 89]], a magnitude 13.5 [[Astronomy:Peculiar galaxy|peculiar]] [[Spiral galaxy|spiral galaxy]] in the constellation [[Astronomy:Phoenix (constellation)|Phoenix]] and a member of [[Astronomy:Robert's Quartet|Robert's Quartet]].

== In sports ==
* The Oklahoma Redhawks, an American minor league baseball team, were formerly known as the Oklahoma 89ers (1962–1997). The number alludes to the Land Run of 1889, when the Unassigned Lands of Oklahoma were opened to white settlement. The team's home of Oklahoma City was founded during this event.
* In Rugby, an "89" or eight-nine move is a phase following a scrum, in which the number 8 catches the ball and transfers it to number 9 (scrum half).
* The Elite 89 Award is presented by the U.S. NCAA to the participant in each of the NCAA's 89 championship finals with the highest grade point average.
* ''89'', a 2017 film about a football match, between Liverpool and Arsenal in 1989.

== In other fields ==
[[Image:TI-89.jpg|thumb|80px|TI-89]]
[[Image:Diaethria clymena or Cramer's Eighty-eight.jpg underside Tr.jpg|thumb|''[[Biology:Diaethria clymena|Diaethria clymena]]'' eyespots]]
'''Eighty-nine''' is also:

*The designation of Interstate 89, a freeway that runs from New Hampshire to Vermont<ref>{{cite web|url=https://www.interstate-guide.com/i-089.html|agency=Interstate Guide|title=Interstate 89|access-date=December 3, 2018}}</ref>
*The designation of U.S. Route 89, a north–south highway that runs from Montana to Arizona
*The [[ISBN]] Group Identifier for books published in [[Place:Korea|Korea]]
*"Pop Song 89" by R.E.M.
* A model of the Texas Instruments calculator [[Software:TI-89 series|TI-89]]
* California Proposition 89, a 2006 California ballot initiative on campaign finance reform
* The title of a currently-unreleased song by Bon Iver
* The greatest number of verses in a chapter of a book of the Bible other than the Book of Psalms—specifically Numbers chapter 7.
* The number of units of each colour in the board game Blokus
* The number of the French department Yonne
* ''Information Is Beautiful'' cites eighty-nine as one of the words censored on the Chinese internet.<ref>{{cite web |url=http://www.informationisbeautiful.net/2010/what-does-china-censor-online/ |title=What Does China Censor Online? |website=www.informationisbeautiful.net |access-date=28 May 2015}}</ref>

==See also==
*[[Hellin's law]]

==References==
<references/>


[[Category:Integers]]

{{Sourceattribution|89 (number)}}