Properties of the Number 15421

Fifteen Thousand Four Hundred Twenty-One

Basics

Value: 15420 → 15421 → 15422

Parity: odd

Prime: No

Previous Prime: 15413

Next Prime: 15427

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 7 × 2203

Divisors: 1, 7, 2203, 15421

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11110000111101

Octal: 36075

Duodecimal: 8B11

Hexadecimal: 3c3d

Square: 237807241

Square Root: 124.18131904598211

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 read by rows: 3-Stirling numbers of the second kind. A143495

a(n) = n*(5·n² - 2)/3. A4466

Triangle read by rows: T(n,k) = number of forests of k labeled rooted trees of height at most 1, with n labels, where any root may contain >= 1 labels, n >= 0, 0 <= k <= n. A143395

Expansion of 1/((1-3x)*(1-4x)*(1-5x)*(1-6x)). A28025

Crystal ball sequence for A₄ lattice. A8384

a(n) = A108625(n,2·n). A363867

Series expansion of the exponential generating function exp(-tridend(-x)) - 1 where tridend(x) = (1 - 3·x - sqrt(1-6·x+x²)) / (4·x) (A001003). A383991

Triangle read by rows: T(n,k) (1 <= k <= n) = Steffensen's bracket function [n,n-k]. A241168

Partial sums of usigma(n)²: square of the sum of unitary divisors of n. A74789

a(n) = ceiling(2ⁿ⁺¹/n). A53639