Properties of the Number 287

Two Hundred Eighty-Seven

Basics

Value: 286 → 287 → 288

Parity: odd

Prime: No

Previous Prime: 283

Next Prime: 293

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 7 × 41

Divisors: 1, 7, 41, 287

Polygonal

Triangular: No

Square: No

Pentagonal: Yes

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100011111

Octal: 437

Duodecimal: 1BB

Hexadecimal: 11f

Square: 82369

Square Root: 16.941074346097416

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Pentagonal numbers: a(n) = n*(3·n-1)/2. A326

Generalized pentagonal numbers: m*(3·m - 1)/2, m = 0, +-1, +-2, +-3, .... A1318

Odd semiprimes: odd numbers divisible by exactly 2 primes (counted with multiplicity). A46315

Numbers that are the sum of 4 but no fewer nonzero squares. A4215

Odd numbers of the form p·q where p and q are distinct primes. A46388

Numbers m such that 6m-1, 6m+1 are twin primes. A2822

a(n) = 2·n² - 1. A56220

Ludic numbers: apply the same sieve as Eratosthenes, but cross off every k-th remaining number. A3309

Multiples of 7. A8589

a(n) = 6·n + 5. A16969