Properties of the Number 18581

Eighteen Thousand Five Hundred Eighty-One

Basics

Value: 18580 → 18581 → 18582

Parity: odd

Prime: No

Previous Prime: 18553

Next Prime: 18583

Digit Sum: 23

Digital Root: 5

Palindrome: Yes

Factorization: 17 × 1093

Divisors: 1, 17, 1093, 18581

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 100100010010101

Octal: 44225

Duodecimal: A905

Hexadecimal: 4895

Square: 345253561

Square Root: 136.31214179228496

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

Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 10. A31423

Modified Schroeder numbers for q=3. A114292

Number of integer partitions of the n-th semiprime into semiprimes. A338902

G.f.: 1/(1-G001190), where G001190 = x + x² + x³ + 2x⁴ + 3x⁵ + ... is the g.f. for the Wedderburn-Etherington numbers A001190. A85748

a(1) = 8; a(n) = smallest palindromic number of the form k·a(n-1) + 1 with k > 1. A69509

Rounded total surface area of a regular dodecahedron with edge length n. A71397

First row of Modified Schroeder numbers for q=3 (A114292). A114296

Numerator of Euler(n,1/3). A156179

Palindromes in A085932. A85933

Numbers m such that m² divides 2^k - 1 for some k, 0 < k <= m. A246503