Properties of the Number 20540

Twenty Thousand Five Hundred Forty

Basics

Value: 20539 → 20540 → 20541

Parity: even

Prime: No

Previous Prime: 20533

Next Prime: 20543

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 2 ² × 5 × 13 × 79

Divisors: 1, 2, 4, 5, 10, 13, 20, 26, 52, 65

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000000111100

Octal: 50074

Duodecimal: BA78

Hexadecimal: 503c

Square: 421891600

Square Root: 143.31782861877304

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

Square pyramidal numbers: a(n) = 0² + 1² + 2² + ... + n² = n*(n+1)*(2·n+1)/6. A330

Structured rhombic dodecahedral numbers (vertex structure 9). A100157

Numbers k such that k² divides 21^k-1. A128401

Number of Sylvester classes of 3-packed words of degree n. A243659

Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = (-1)ⁿ * ∑_j=0..n (-2)^j * binomial(n,j) * binomial(k·n+j+1,n)/(k·n+j+1). A336573

Number of integer partitions of n such that it is possible to choose a different constant integer partition of each part. A387330

Nonnegative values·of solutions (x, y) to the Diophantine equation x² + (x+199)² = y². A129993

1/24 of product of three numbers: n-th prime, previous and following number. A127922

a(0)=0; then a(4·k+1)=a(4·k)+(4·k+1)², a(4·k+2)=a(4·k+1)+(4·k+3)², a(4·k+3)=a(4·k+2)+(4·k+2)², a(4·k+4)=a(4·k+3)+(4·k+4)². A115391

The number of binary pattern classes in the (2,n)-rectangular grid with 3 '1's and (2n-3) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other. A225972