Properties of the Number 21392

Twenty-One Thousand Three Hundred Ninety-Two

Basics

Value: 21391 → 21392 → 21393

Parity: even

Prime: No

Previous Prime: 21391

Next Prime: 21397

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 2 ⁴ × 7 × 191

Divisors: 1, 2, 4, 7, 8, 14, 16, 28, 56, 112

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001110010000

Octal: 51620

Duodecimal: 10468

Hexadecimal: 5390

Square: 457617664

Square Root: 146.26004239025778

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: T(n,k) = number of primitive (aperiodic) reversible string structures with n beads using exactly k different colors. A276544

The number of non-equivalent distinguishing coloring partitions of the path on n vertices (n>=1) with exactly k parts (k>=1). Regular triangle read by rows: the rows are indexed by n, the number of vertices of the path, and the columns are indexed by k, the number of parts. A309748

Triangle in which row n lists the coefficients in ∏_k=1..n (1 + k·x + x²), for n>=0, as read by rows. A249790

Number of primitive (aperiodic) reversible string structures with n beads using exactly five different colors. A56339

Expansion of e.g.f. sec(sinh(x)*tan(x)) (only even powers). A12552

Triangle read by rows: T(n,k) = number of partial idempotent mappings (of an n-chain) with (right) waist exactly k. A258579

Central coefficients in ∏_k=1..n (1 + k·y + y²). A201826

G.f.: ∑_n>=0 xⁿ * ∏_k=1..n (1 + k·x + x²). A202476

Coefficients of y^n-1 in ∏_k=1..n (1 + k·y + y²) for n >= 1. A202474

Numbers k such that the cyclic group of order k is not a Hajós group. A102562