Properties of the Number 18515

Eighteen Thousand Five Hundred Fifteen

Basics

Value: 18514 → 18515 → 18516

Parity: odd

Prime: No

Previous Prime: 18503

Next Prime: 18517

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 5 × 7 × 23 ²

Divisors: 1, 5, 7, 23, 35, 115, 161, 529, 805, 2645

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100100001010011

Octal: 44123

Duodecimal: A86B

Hexadecimal: 4853

Square: 342805225

Square Root: 136.06983501129116

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

Triangle T(n,k) read by rows giving number of labeled mappings (or functional digraphs) from n points to themselves (endofunctions) with exactly k cycles, k=1..n. A60281

Product of n with sum of next n consecutive integers. A36659

Numbers that match polynomials over {0,1} that have a factor containing -3 as a coefficient; see Comments. A208182

Numbers n for which the digital sum contains the same distinct digits as the digital product but the digital sum is not equal to the digital product. A249335

Least k such that the sum of the semiprime divisors equals n times the sum of the prime divisors, or 0 if no such k exists. A227419

Composite numbers k such that σ(k + σ(k)) = 2*σ(k). A246858

Expansion of (4 + 15·x - 35·x² + 20·x³ - 2·x⁵)/(1 - x)⁵. A257600

a(n) = (n⁴ + 20·n³ + 125·n² + 250·n + 24)/12. A257601

Number of endofunctions on [n] with exactly four cycles. A273435

a(0) = 1, a(n) = 17·n² + 2 for n>0. A10007