Properties of the Number 31681

Thirty-One Thousand Six Hundred Eighty-One

Basics

Value: 31680 → 31681 → 31682

Parity: odd

Prime: No

Previous Prime: 31667

Next Prime: 31687

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 13 × 2437

Divisors: 1, 13, 2437, 31681

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 111101111000001

Octal: 75701

Duodecimal: 16401

Hexadecimal: 7bc1

Square: 1003685761

Square Root: 177.99157283422156

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

Expansion of (1 - x)/(1 - 32·x + x²). A159674

a(n) = n³ - n² - 2·n + 1. A123972

First occurrence of difference n between two consecutive terms of A000404. a(n) gives the upper term. The lower term is A355237. A355238

Denominators of continued fraction convergents to sqrt(255). A41479

a(n) = ∑_i=1..n LookAndSay(i). A79664

sech(tan(arcsinh(x)))=1-1/2!*x²+1/4!*x⁴-1/6!*x⁶+449/8!*x⁸... A12169

Expansion of x*(1 + x)/(1 - 32·x + x²). A159675

Expansion of 64·x²/(1 - 1023·x + 1023·x² - x³). A159677

Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 93. A31681