105 (
one hundred [and] five) is
the
natural number following
104 and preceding
106.
In mathematics
105 is a
triangular number, a
12-gonal number and a
Zeisel number. It is a
sphenic number, and is the product of three
consecutive
prime numbers. 105 is the
double factorial of 7. It is also
the sum of the first five
square
pyramidal numbers.
105 comes in the middle of the
prime
quadruplet (101, 103, 107, 109). The only other such odd
numbers less than a thousand are 15, 195 and 825. 105 is also a
pseudoprime to the prime bases 13, 29,
41, 43, 71, 83 and 97. The distinct prime factors of 105 add up to
15, and so do those of 104, hence the two numbers form a
Ruth-Aaron pair under the first
definition.
105 is also a number
n for which n - 2^k is prime, for 0 k
log_2(n). (This even works up to k = 8, ignoring the negative
sign.)
105 is the smallest integer such that the factorization of x^n-1
over
Q includes coefficients other than \pm
1.
In science
In astronomy,
- Messier object M105, a magnitude 11.0
elliptical galaxy in the constellation Leo
- The New General Catalogue
object NGC105, a magnitude 13.2 spiral galaxy in the constellation Pisces
- Asteroid 105
Artemis
- The Saros number of the solar
eclipse series which began on 499 March and ended on 1779 May.
The duration of Saros series 105 was 1280.1 years, and it contained
72 solar eclipses.
- The Saros number of the lunar
eclipse series which began on 566 August and ended on 1882
October. The duration of Saros series 105 was 1316.2 years, and it
contained 74 lunar eclipses.
In other fields
105 is also:
- The year AD 105 or 105
BC.
- The designation of some spur routes of Interstate 5.
- A film format introduced by Kodak for
their first folding camera. See 120
film.
- The name of a song on Smash Mouth's
Get the Picture? CD (2003)
- The name of a road bicycle
groupset from Shimano.
- The number of surat al-Fil in the Qur'an.
- The prison cell where Doctor
Manette lived, in Charles
Dickens's "A Tale of Two
Cities"
- Radio stations such as
Power 105 WWPR-FM, New York City, and J105 KJOT, Boise, Idaho
- The 105th United States
Congress met from January 3, 1997 to January 3, 1999, during
Bill Clinton administration
- The Republic F-105
Thunderchief, commonly known as the "Thud" by its crews, was a
single-seat supersonic fighter-bomber used by the United States Air Force
- The USS Pioneer was a U.S.
Navy Auk class minesweeper
during World War II
- Bo 105 is a light, twin-engine,
multi-purpose utility helicopter
developed in 1991
- The
police emergency telephone
number in Peru
- PT 105 was a US Navy PT boat in World War
II commanded by Dick Keresey, which fought in the same battle as
PT 109
- East 105th–Quincy is a station on the RTA Rapid Transit Red Line in Cleveland, Ohio
- The Famous Winter War lasted 105 days
in 1939-1940
In the space program
In sports
See also
References
- Wells, D. The Penguin Dictionary of Curious and Interesting
Numbers London: Penguin Group. (1987): 134