287 (number)

← 286 287 288 →
← 200 210 220 230 240 250 260 270 280 290 → List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
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

• 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 6(287)-1 and 6(287)+1 are both prime. ^[5]

References

1. "Composite numbers". mathworld.wolfram.com.
2. "Pentagonal number". mathworld.wolfram.com.
3. Sloane, N. J. A. (ed.). "SequenceA046315(Odd semiprimes: odd numbers divisible by exactly 2 primes (counted with multiplicity))". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
4. Sloane, N. J. A. (ed.). "SequenceA004215(Numbers that are the sum of 4 but no fewer nonzero squares)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
5. Sloane, N. J. A. (ed.). "SequenceA002822(Numbers m such that 6m-1, 6m+1 are twin primes)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.