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109 (number) 
Summary
109 (one hundred [and] nine) is the natural number following 108 and preceding 110.
| ||||
|---|---|---|---|---|
| Cardinal | one hundred nine | |||
| Ordinal | 109th (one hundred ninth) | |||
| Factorization | prime | |||
| Prime | 29th | |||
| Divisors | 1, 109 | |||
| Greek numeral | ΡΘ´ | |||
| Roman numeral | CIX | |||
| Binary | 11011012 | |||
| Ternary | 110013 | |||
| Octal | 1558 | |||
| Duodecimal | 9112 | |||
| Hexadecimal | 6D16 | |||
In mathematicsEdit
109 is the 29th prime number. As 29 is itself prime, 109 is a super-prime.[1] The previous prime is 107, making them both twin primes.[2] 109 is a centered triangular number.[3]
There are exactly 109 different families of subsets of a three-element set whose union includes all three elements,[4] 109 different loops (invertible but not necessarily associative binary operations with an identity) on six elements, [5] and 109 squares on an infinite chessboard that can be reached by a knight within three moves.[6]
In other fieldsEdit
- 109 is the atomic number of meitnerium.[7]
- The diameter of the sun is about 109.1 to 109.5 the diameter of the earth.
See alsoEdit
ReferencesEdit
- ^ Sloane, N. J. A. (ed.). "Sequence A006450 (Primes with prime subscripts)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A006512 (Greater of twin primes)". 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 A003465 (Number of ways to cover an n-set)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A057771 (Number of loops (quasigroups with an identity element) of order n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A018836 (Number of squares on infinite chess-board at ≤ n knight's moves from a fixed square)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Emsley, John (2011), Nature's Building Blocks: An A-Z Guide to the Elements, Oxford University Press, p. 316, ISBN 9780199605637.