85 (eighty-five) is the natural number following 84 and preceding 86.
| ||||
---|---|---|---|---|
Cardinal | eighty-five | |||
Ordinal | 85th (eighty-fifth) | |||
Factorization | 5 × 17 | |||
Divisors | 1, 5, 17, 85 | |||
Greek numeral | ΠΕ´ | |||
Roman numeral | LXXXV | |||
Binary | 10101012 | |||
Ternary | 100113 | |||
Senary | 2216 | |||
Octal | 1258 | |||
Duodecimal | 7112 | |||
Hexadecimal | 5516 |
In mathematics
[edit]85 is:
- the product of two prime numbers (5 and 17), and is therefore a semiprime of the form (5.q) where q is prime.
- specifically, the 24th Semiprime, it being the fourth of the form (5.q).
- together with 86 and 87, forms the second cluster of three consecutive semiprimes; the first comprising 33, 34, 35.[1]
- with a prime aliquot sum of 23 in the short aliquot sequence (85,23,1,0).
- an octahedral number.[2]
- a centered triangular number.[3]
- a centered square number.[4]
- a decagonal number.[5]
- the smallest number that can be expressed as a sum of two squares, with all squares greater than 1, in two ways, 85 = 92 + 22 = 72 + 62.[6]
- the length of the hypotenuse of four Pythagorean triangles.
- a Smith number in decimal.[7]
In astronomy
[edit]- Messier object M85 is a magnitude 10.5 lenticular galaxy in the constellation Coma Berenices
- NGC 85 is a galaxy in the constellation Andromeda
- 85 Io is a large main belt asteroid
- 85 Pegasi is a multiple star system in constellation of Pegasus
- 85 Ceti is a variable star in the constellation of Cetus
- 85D/Boethin is a periodic comet
In titles and names
[edit]- Federalist No. 85, by Alexander Hamilton, the last of The Federalist Papers (1788)
- The 85 Ways to Tie a Tie, a book by Thomas Fink and Yong Mao
- 85 Days: The Last Campaign of Robert Kennedy, a book by Jules Witcover
- Live/1975–85, an album of live recordings by Bruce Springsteen (1986)
- 80–85, a compilation album by Bad Religion (1991)
- Cupid & Psyche 85, an album by band Scritti Politti (1985)
- 45/85 was a television documentary on World War II
- Minuscule 85, Papyrus 85, Lectionary 85 are early Greek manuscripts of the New Testament
- "85", a 2000 rap single by YoungBloodz, from their album Against Da Grain
- 85°C, a Taiwanese coffee store chain.
In sports
[edit]In U.S. college athletics, schools that are members of NCAA Division I are limited to providing athletic scholarships to a maximum of 85 football players in a given season. The specifics vary by the two Division I football subdivisions:
- In the top-level FBS, each player provided with a scholarship may, and almost always does, receive a full scholarship.
- In the second-level FCS, schools are allowed to provide football-related athletic aid equivalent to 63 full scholarships, but this aid may be divided among up to 85 players as the schools see fit.
In other fields
[edit]- The year AD 85, 85 BC, or 1985.
- The Muslim calendar year 85 AH.
- The atomic number of the chemical element astatine
- The number of the French department Vendée
- The ISBN Group Identifier for books published in Brazil
- The radix of the Ascii85 (sometimes called Base85) binary-to-text encoding
- The IQ and nickname of Aaron in Alien 3
- The number worn by Chad Ochocinco, whose name means "eight five" in Spanish
- Arabigere 85 is a village in India
- E85 fuel is 85% ethanol and 15% conventional gasoline
- MCS-85 was a family of Intel processors including the 8085
- TI-85 was a graphing pocket calculator by Texas Instruments
- KC 85 was a family of small computers built in East Germany in the 1980s
- PMD 85 was a personal computer built in Czechoslovakia in 1985
- Learjet 85 is an all-composite plane being developed by Bombardier Aerospace
- British Rail Class 85, a category of UK train locomotives
- DRG Class 85, a category of German train locomotives
- TK85 was a clone of the Sinclair ZX81 made in Brazil in 1983
- Lima Site 85 was a battle in the Vietnam War
- A85 is the Dutch Defence in the Encyclopaedia of Chess
- EF 85mm is a photographic camera lens by Canon
- F85 (disambiguation), multiple uses
- Part of the assignation for the Toyota AE85, commonly referred to as an "eight-five".
- KiHa 85 series is a diesel Limited express train that ran in Japan until 2023.
- HC85 series is the successor of KiHa 85 and is a hybrid diesel limited express train.
In military technology
[edit]- 85mm is a common caliber for cannons
- SU-85 was a Soviet tank
- TR-85 was a Romanian battle tank
- Tu-85 was a prototype Soviet bomber
- ASU-85 a Soviet self-propelled gun
- CZ 85 is a Czech 9mm semiautomatic pistol
- PT-85 is a Korean tank
- 7.62 Tkiv 85 is a Finnish army rifle
- HG 85 is a Swiss fragmentation grenade
- Taurus Model 85, a 9mm revolver made in Brazil
See also
[edit]References
[edit]- ^ Sloane, N. J. A. (ed.). "Sequence A056809 (Numbers k such that k, k+1 and k+2 are products of two primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A005900 (Octahedral numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A005448 (Centered triangular numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A001844 (Centered square numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A001107 (10-gonal (or decagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A007692 (Numbers that are the sum of 2 non-zero squares in 2 or more ways)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.. The two smaller numbers on this list, 50 and 65, have 1 as one of the squares in their representations as sums of two squares.
- ^ Sloane, N. J. A. (ed.). "Sequence A006753 (Smith numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
External links
[edit]- 85
- Jorge Stolfi, The Hollywood Constant.