Properties of the Number -20808

Twenty Thousand Eight Hundred Eight

Basics

Value: -20809 → -20808 → -20807

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ³ × 3 ² × 17 ²

Divisors: 1, 2, 3, 4, 6, 8, 9, 12, 17, 18

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -101000101001000

Octal: -50510

Duodecimal: -10060

Hexadecimal: -5148

Square: 432972864

Square Root: 144.2497833620557

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

-1 + ∏_n>=1 (1 + xⁿ)^a(n) = g.f. of A000040 (prime numbers). A305871

Low-temperature specific heat expansion for hexagonal lattice (Potts model, q=3). A57384

Low-temperature partition function expansion for Kagome net (Potts model, q=4). A57405

a(n) = n²*(n² - 1)/4. A6011

a(n) = (1/4)*floor(n/2)*floor((n-1)/2)*floor((n-2)/2)*floor((n-3)/2). A28723

a(n) = 18·n². A195321

Averages of twin prime pairs k such that k·2 and k/2 are squares. A154670

Sum of positive cranks minus the sum of positive ranks of all partitions of n. A195012

Powerful numbers (definition 1) sandwiched between twin primes. A113839

Number n such that Fibonacci(n) is divisible by n, n + 1 and n - 1. A221018