287 (number)
| ||||
|---|---|---|---|---|
| Cardinal | two hundred eighty-seven | |||
| Ordinal | 287th (two hundred eighty-seventh) | |||
| Factorization | 7 × 41 | |||
| Divisors | 1, 7, 41, 287 | |||
| Greek numeral | ΣΠΖ´ | |||
| Roman numeral | CCLXXXVII, cclxxxvii | |||
| Binary | 1000111112 | |||
| Ternary | 1011223 | |||
| Senary | 11556 | |||
| Octal | 4378 | |||
| Duodecimal | 1BB12 | |||
| Hexadecimal | 11F16 | |||
287 is the natural number following 286 and preceding 288.
In mathematics
[edit]- 287 is an odd composite number with 2 prime factors.[1]
- 287 is the sum of consecutive primes in three different ways, 89+97+101, 43+53+59+61+67, and 17+19+23+29+31+37+41+43+47
- 287 is a pentagonal number which follows the concept of triangular numbers.[2]
- 287 is an odd semiprime number.[3]
- 287 is the sum of exactly 4 nonzero squares.[4]
- 287 is a number where 2(287)-1 and 2(287)+1 are both prime.[5]
References
[edit]- ^ "Composite numbers". mathworld.wolfram.com.
- ^ "Pentagonal number". mathworld.wolfram.com.
- ^ Sloane, N. J. A. (ed.). "Sequence A046315 (Odd semiprimes: odd numbers divisible by exactly 2 primes (counted with multiplicity))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A004215 (Numbers that are the sum of 4 but no fewer nonzero squares)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A002822 (Numbers m such that 6m-1, 6m+1 are twin primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.