Properties of the Number 31981

Thirty-One Thousand Nine Hundred Eighty-One

Basics

Value: 31980 → 31981 → 31982

Parity: odd

Prime: Yes

Previous Prime: 31973

Next Prime: 31991

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 31981

Divisors: 1, 31981

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111110011101101

Octal: 76355

Duodecimal: 16611

Hexadecimal: 7ced

Square: 1022784361

Square Root: 178.83232370016333

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

a(n) = 1 + n*(n+1)*(n-1)/2. A158842

Number of (w,x,y,z) with all terms in {1,...,n} and w³<=x³+y³+z³. A212098

Primes of the form p=floor(T/6), T are triangular numbers. A171595

Primes of the form 6n² + 7. A201601

a(n) = gpf(lpf(2^prime(n) - 1) - 1) where prime(n) is the n-th prime. A292238

Number of walks within N³ (the first octant of Z³) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (0, 1, 1), (1, 0, 1), (1, 1, -1), (1, 1, 1)}. A151232

Primes that are the average of the members of more than one emirp pair. A178587

Least hypotenuse, c, of a Primitive Pythagorean Triangle (PPT) such that the difference between it, c, and its greater leg, b, is n; or 0 if no such PPT exists. A277534

a(1) = 1, a(2) = 2, a(n) = smallest number not the sum of cubes of >= 1 distinct earlier terms. A31981