Properties of the Number 31661

Thirty-One Thousand Six Hundred Sixty-One

Basics

Value: 31660 → 31661 → 31662

Parity: odd

Prime: No

Previous Prime: 31657

Next Prime: 31663

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 7 × 4523

Divisors: 1, 7, 4523, 31661

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 111101110101101

Octal: 75655

Duodecimal: 163A5

Hexadecimal: 7bad

Square: 1002418921

Square Root: 177.93538152936307

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

T(n,k) = Number of (n+1) X (k+1) 0..2 arrays with the maximum minus the lower median of every 2 X 2 subblock equal. A237850

E.g.f. A(x) satisfies A(x) = 1/( 1 - A(x) * sin(x·A(x)) ). A381182

Number of (n+1)X(2+1) 0..2 arrays with the maximum minus the lower median of every 2X2 subblock equal. A237844

Number of (n+1)X(3+1) 0..2 arrays with the maximum minus the lower median of every 2X2 subblock equal. A237845

Number of trees on n nodes with forbidden limbs. A14281

Number of nX2 0..3 arrays of the median of the corresponding element, the element to the east and the element to the south in a larger (n+1)X3 0..3 array. A229101

Denominators of approximations j/k for π such that abs(j/k - π)*sqrt(5)*k² < 1. A346534

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 73. A31661

Smallest number requiring n 1's to build using +, -, *, and ^. A347983