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Properties of the Number 20904

Twenty Thousand Nine Hundred Four

Basics

Value: 20903 → 20904 → 20905

Parity: even

Prime: No

Previous Prime: 20903

Next Prime: 20921

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 2 3 × 3 × 13 × 67

Divisors: 1, 2, 3, 4, 6, 8, 12, 13, 24, 26

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000110101000

Octal: 50650

Duodecimal: 10120

Hexadecimal: 51a8

Square: 436977216

Square Root: 144.58215657542254

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

4 times 9-gonal numbers: a(n) = 2·n*(7·n-5). A152760
Numbers that are the sum of six fifth powers in two or more ways. A345507
Numbers that are the sum of six fifth powers in exactly two ways. A346357
Antidiagonal sums of the convolution array A213587. A213589
a(n) = ∑d∣4 φ(d)*n4/d. A54603
a(n) = r4(n2 + 1), where r4(k) is the number of ways of writing k as a sum of 4 squares (A000118). A333173
Number of (n+2)X(7+2) 0..3 arrays with every consecutive three elements in every row and column not having exactly two distinct values, and in every diagonal and antidiagonal having exactly two distinct values, and new values 0 upwards introduced in row major order. A253024
a(n) = 5·Fibonacci(n) + (-1)n. A371843
Numbers whose base-12 representation has exactly 5 runs. A43654
Dedekind numbers or Dedekind's problem: number of monotone Boolean functions of n variables, number of antichains of subsets of an n-set, number of elements in a free distributive lattice on n generators, number of Sperner families. A372