Properties of the Number 12181

Twelve Thousand One Hundred Eighty-One

Basics

Value: 12180 → 12181 → 12182

Parity: odd

Prime: No

Previous Prime: 12163

Next Prime: 12197

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 13 × 937

Divisors: 1, 13, 937, 12181

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10111110010101

Octal: 27625

Duodecimal: 7071

Hexadecimal: 2f95

Square: 148376761

Square Root: 110.3675676999362

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 nXk 0..1 arrays with every 1 horizontally, diagonally or antidiagonally adjacent to 0, 1 or 4 neighboring 1s. A297682

Centered 28-gonal numbers. A195314

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

a(n) = (15·n² + 9·n + 2)/2. A220083

Define C(n) by the recursion C(0) = 5·i where i² = -1, C(n+1) = 1/(1 + C(n)), then a(n) = 5*(-1)ⁿ/Im(C(n)) where Im(z) denotes the imaginary part of z. A69962

Number T(n,k) of partitions of n into k parts where each block of part i with multiplicity j is marked with a word of length i·j over an n-ary alphabet whose letters appear in alphabetical order and all n letters occur exactly once in the partition; triangle T(n,k), n>=0, 0<=k<=n, read by rows. A364310

Expansion of e.g.f. Series_Reversion(log(1+x) - x³). A391954

Expansion of 1/(1-x-3·x²-4·x³-2·x⁴). A124861

Numbers k such that 2·k!! - 1 is prime. A215779

Number of compositions of n having exactly six fixed points. A240741