Properties of the Number 31391

Thirty-One Thousand Three Hundred Ninety-One

Basics

Value: 31390 → 31391 → 31392

Parity: odd

Prime: Yes

Previous Prime: 31387

Next Prime: 31393

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 31391

Divisors: 1, 31391

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111101010011111

Octal: 75237

Duodecimal: 161BB

Hexadecimal: 7a9f

Square: 985394881

Square Root: 177.17505467757022

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

Smallest prime p of form p = 8k-1 such that first n primes (p₁=2, ..., p_n) are quadratic residues mod p. A2223

Least negative pseudosquare modulo the first n odd primes. A45535

a(n) is the least number m such that the n-th prime is the least quadratic nonresidue modulo m. A229

Smallest prime p such that the maximum run length of consecutive positive quadratic residues modulo p is n. A97159

Records in A000229. A133435

Smallest integer >= 2 that is not the sum of 2 positive integers whose prime factors are all <= p(n), the n-th prime. A62241

Smallest prime p modulo which numbers 1,2,...,n are quadratic residues. A147969

Least odd number k such that x' = k has n solutions, where x' is the arithmetic derivative (A003415) of x. A189560

Primes p such that continued fraction of (1 + sqrt(p))/2 has period 12 : primes in A146336. A146357

Primes corresponding to the records in the sequence of smallest positive quadratic nonresidues (A053760). A147970