135 (number)

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Short description: Natural number
← 134 135 136 →
Cardinalone hundred thirty-five
Ordinal135th
(one hundred thirty-fifth)
Factorization33 × 5
Divisors1, 3, 5, 9, 15, 27, 45, 135
Greek numeralΡΛΕ´
Roman numeralCXXXV
Binary100001112
Ternary120003
Quaternary20134
Quinary10205
Senary3436
Octal2078
DuodecimalB312
Hexadecimal8716
Vigesimal6F20
Base 363R36

135 (one hundred [and] thirty-five) is the natural number following 134 and preceding 136.

In mathematics

135 is the number of partitions of 14, and the number of rooted trees with 15 nodes and height at most 2.[1] 135 is 5-smooth, since its prime factorization is [math]\displaystyle{ 3^3 \times 5 }[/math], and a Harshad number in decimal.[2][3]

Using its own digits, 135 in base-10 can be expressed in operations as the sum of consecutive powers of its digits, and as a sum-product number:

[math]\displaystyle{ 135 = 1^1 + 3^2 + 5^3 }[/math][4]
[math]\displaystyle{ 135 = (1 + 3 + 5)(1 \times 3 \times 5) }[/math][5]

135 is the number of degrees in the internal angle of a regular eight-sided octagon, and the number of nodes inside a regular nonagon from the intersection of its diagonals and sides.[6] Also:

While the central angle of a regular octagon is 135 ÷ 3 = 45 degrees, 4.5 is the harmonic mean of all eight divisors of 135.

The aliquot sum of 135 is 105, which is the 14th triangular number, or equivalently the sum of the first fourteen non-zero positive integers.[8][9]

There are 135 total Krotenheerdt k-uniform tilings for k < 8, with no other such tilings for higher k.[10]

There are a total of 135 primes between 1,000 and 2,000.

[math]\displaystyle{ 135 = 11 n^2 + 11 n + 3 }[/math] for [math]\displaystyle{ n = 3 }[/math] is a polynomial that plays an essential role in Apéry's proof that [math]\displaystyle{ \zeta(3) }[/math] is irrational.[citation needed]

In other fields

  • The year AD 135 or 135 BC.
  • 135 AH is a year in the Islamic calendar that corresponds to 752–753 CE.
  • 135 Hertha is a large main belt asteroid which orbits among the Nysa asteroid family.
  • 135 film, the cartridge version of 35mm photographic film, used widely in still photography.
  • The Canon FD 135 mm lens.
  • In astrology, when two planets are 135 degrees apart, they are in an astrological aspect called a sesquiquadrate. The aspect was first used by Johannes Kepler.
  • Sonnet 135 by William Shakespeare.
  • Municipal District of Peace No. 135, a municipal district in northwest Alberta, Canada.
  • Enoch Cree Nation 135 Indian reserve in Alberta, Canada, is home to the Enoch Cree Nation.
  • The EZ 135 Drive removable hard disk drive introduced by SyQuest Technology in 1995.
  • OC-135B Open Skies United States Air Force observation aircraft flies unarmed observation flights over nations of the Treaty on Open Skies.

See also

  • List of highways numbered 135
  • United Nations Security Council Resolution 135
  • United States Supreme Court cases, Volume 135

References

  1. Sloane, N. J. A., ed. "Sequence A000041 (The number of partitions of n (the partition numbers))". OEIS Foundation. https://oeis.org/A000041. Retrieved 2022-12-05. 
  2. Sloane, N. J. A., ed. "Sequence A005349 (Niven (or Harshad, or harshad) numbers: numbers that are divisible by the sum of their digits.)". OEIS Foundation. https://oeis.org/A005349. Retrieved 2022-12-05. 
  3. Sloane, N. J. A., ed. "Sequence A051037 (5-smooth numbers, i.e., numbers whose prime divisors are all less than or equal to five.)". OEIS Foundation. https://oeis.org/A051037. Retrieved 2022-12-05. 
  4. "Sloane's A032799: Numbers n such that n equals the sum of its digits raised to the consecutive powers (1,2,3,...)". OEIS Foundation. https://oeis.org/A032799. 
  5. "Sloane's A038369 : Numbers n such that n = (product of digits of n) * (sum of digits of n)". OEIS Foundation. https://oeis.org/A038369. 
  6. Sloane, N. J. A., ed. "Sequence A007569 (Number of nodes in regular n-gon with all diagonals drawn.)". OEIS Foundation. https://oeis.org/A007569. Retrieved 2023-04-04. 
  7. Sloane, N. J. A., ed. "Sequence A000010 (Euler totient function phi(n): count numbers less than or equal to n and prime to n.)". OEIS Foundation. https://oeis.org/A000010. Retrieved 2022-12-06. 
  8. Sloane, N. J. A., ed. "Sequence A001065 (Sum of proper divisors (or aliquot parts) of n: sum of divisors of n that are less than n.)". OEIS Foundation. https://oeis.org/A001065. Retrieved 2022-12-06. 
  9. Sloane, N. J. A., ed. "Sequence A000217 (Triangular numbers)". OEIS Foundation. https://oeis.org/A000217. Retrieved 2022-12-06. 
  10. Sloane, N. J. A., ed. "Sequence A068600 (Number of n-uniform tilings having n different arrangements of polygons about their vertices.)". OEIS Foundation. https://oeis.org/A068600. Retrieved 2023-01-09.