115 (number)
|
||||
|---|---|---|---|---|
| Cardinal | one hundred fifteen | |||
| Ordinal | 115th (one hundred and fifteenth) |
|||
| Factorization | 5 × 23 | |||
| Divisors | 1, 5, 23, 115 | |||
| Roman numeral | CXV | |||
| Binary | 11100112 | |||
| Ternary | 110213 | |||
| Quaternary | 13034 | |||
| Quinary | 4305 | |||
| Senary | 3116 | |||
| Octal | 1638 | |||
| Duodecimal | 9712 | |||
| Hexadecimal | 7316 | |||
| Vigesimal | 5F20 | |||
| Base 36 | 3736 | |||
115 (one hundred [and] fifteen) is the natural number following 114 and preceding 116.
In mathematics[edit]
115 has a square sum of divisors:
It is unknown whether the set of numbers with this property is infinite, but this would follow from the truth of the Bunyakovsky conjecture on polynomials with infinitely many prime values.[1]
There are 115 different rooted trees with exactly eight nodes,[2] 115 inequivalent ways of placing six rooks on a 6 × 6 chess board in such a way that no two of the rooks attack each other,[3] and 115 solutions to the stamp folding problem for a strip of seven stamps.[4]
115 is also a heptagonal pyramidal number.[5] The 115th Woodall number,
is a prime number.[6]
In other fields[edit]
115 is also the fire service emergency number in Mauritius[7] and Italy,[8] and the ambulance emergency number in Vietnam.[9]
See also[edit]
References[edit]
- ^ "Sloane's A006532 : Numbers n such that sum of divisors of n is a square", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "Sloane's A000081 : Number of rooted trees with n nodes (or connected functions with a fixed point)", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "Sloane's A000903 : Number of inequivalent ways of placing n nonattacking rooks on n X n board", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "Sloane's A002369 : Number of ways of folding a strip of n rectangular stamps", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "Sloane's A002413 : Heptagonal (or 7-gonal) pyramidal numbers: n*(n+1)*(5*n-2)/6", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "Sloane's A002234 : Numbers n such that the Woodall number n*2^n - 1 is prime", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Cheong-Lum, Roseline Ng (2009), CultureShock! Mauritius: A Survival Guide to Customs and Etiquette, Marshall Cavendish International Asia Pte Ltd, p. 287, ISBN 9789814435604.
- ^ DK Eyewitness Travel Guide: Italy, Penguin, 2013, p. 619, ISBN 9781465414946.
- ^ The Rough Guide to Southeast Asia On A Budget, Penguin, 2014, p. 1286, ISBN 9780241012727.
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
