Properties of the Number 20544

Twenty Thousand Five Hundred Forty-Four

Basics

Value: 20543 → 20544 → 20545

Parity: even

Prime: No

Previous Prime: 20543

Next Prime: 20549

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 2 ⁶ × 3 × 107

Divisors: 1, 2, 3, 4, 6, 8, 12, 16, 24, 32

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000001000000

Octal: 50100

Duodecimal: BA80

Hexadecimal: 5040

Square: 422055936

Square Root: 143.33178293735133

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) gives the number of permutations of the set [n] that contain k occurrences of the subword (132); irregular array read by rows (n >= 0 and 0 <= k <= max(0, floor((n-1)/2))). A197365

a(0)=4; a(n)=n²+a(n-1) for n>0. A153058

a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-3)*a(3) for n >= 4, with initial terms 1, 2, 1, 1. A25243

G.f.: (1 + x⁴ + x⁷ + 2·x⁸ + x⁹ + x¹² + x¹⁶)/∏_i=1..8 (1 - xⁱ). A3405

Number of tournaments on n nodes with a unique winner. A13976

Lower triangular array, called S1hat(-4), related to partition number array A145369. A145370

Decimal representation of the diagonal from the corner to the origin of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 390", based on the 5-celled von Neumann neighborhood. A287981

Number of 2-packed matrices with exactly n nonzero entries. A230880

Number of permutations of [n] containing exactly one occurrence of the consecutive pattern 132. A263885

Number of permutations of symmetric group S_n with an odd number of cycles of length 2 or more. A373340