115 (number)
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Cardinal | one hundred fifteen | |||
Ordinal | 115th (one hundred and fifteenth) |
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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
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
115 is also the fire service emergency number in Mauritius[7] and Italy,[8] and the ambulance emergency number in Vietnam.[9]
See also
References
- ↑ "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.
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