251 (number)
From Infogalactic: the planetary knowledge core
|
||||
|---|---|---|---|---|
| Cardinal | two hundred fifty-one | |||
| Ordinal | 251st (two hundred and fifty-first) |
|||
| Factorization | 251 | |||
| Prime | 54th | |||
| Roman numeral | CCLI | |||
| Binary | 111110112 | |||
| Ternary | 1000223 | |||
| Quaternary | 33234 | |||
| Quinary | 20015 | |||
| Senary | 10556 | |||
| Octal | 3738 | |||
| Duodecimal | 18B12 | |||
| Hexadecimal | FB16 | |||
| Vigesimal | CB20 | |||
| Base 36 | 6Z36 | |||
251 (two hundred [and] fifty-one) is the natural number between 250 and 252. It is also a prime number.
In mathematics
251 is a Sophie Germain prime.[1] Every 5 × 5 matrix has exactly 251 square submatrices.[2] 251 is a de Polignac number, meaning that it is odd and cannot be formed by adding a power of two to a prime number.[3][4] It is the smallest number that can be formed in more than one way by summing three positive cubes:[5][6]
References
- ↑ "Sloane's A005384 : Sophie Germain primes p: 2p+1 is also prime", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ↑ "Sloane's A030662 : Number of combinations of n things from 1 to n at a time, with repeats allowed", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ↑ "Sloane's A006285 : Odd numbers not of form p + 2^x (de Polignac numbers)", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ↑ Lua error in package.lua at line 80: module 'strict' not found..
- ↑ "Sloane's A008917 : Numbers that are the sum of 3 positive cubes in more than one way", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ↑ Lua error in package.lua at line 80: module 'strict' not found..
