Properties of the Number 20918

Twenty Thousand Nine Hundred Eighteen

Basics

Value: 20917 → 20918 → 20919

Parity: even

Prime: No

Previous Prime: 20903

Next Prime: 20921

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 × 10459

Divisors: 1, 2, 10459, 20918

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000110110110

Octal: 50666

Duodecimal: 10132

Hexadecimal: 51b6

Square: 437562724

Square Root: 144.63056385149025

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

Number of unlabeled balanced semi-binary rooted trees with n nodes. A320270

a(n) is twice the smallest k such that A051686(k) = prime(n). A51692

a(0) = 1; thereafter a(n) = 2*(6·n² - 3·n + 1). A386477

Number of nondecreasing arrangements of 10 numbers in 0..n with the last equal to n and each after the second equal to the sum of one or two of the preceding four. A189333

Numbers whose base-12 representation has exactly 5 runs. A43654

a(n)=(2^2ⁿ + 3^2ⁿ + 5^2ⁿ)/19. A132396

Expansion of 1/(1-4·x)^7/2. A20918