Properties of the Number 20919

Twenty Thousand Nine Hundred Nineteen

Basics

Value: 20918 → 20919 → 20920

Parity: odd

Prime: No

Previous Prime: 20903

Next Prime: 20921

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 19 × 367

Divisors: 1, 3, 19, 57, 367, 1101, 6973, 20919

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000110110111

Octal: 50667

Duodecimal: 10133

Hexadecimal: 51b7

Square: 437604561

Square Root: 144.63402089411744

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

Partial sums of A294016. A294017

Denominators a(n) of Pythagorean approximations b(n)/a(n) to π. A195544

Number of quadrilateral regions in a "frame" of size n X n (see Comments in A331776 for definition), divided by 8. A332596

Consecutive states of the linear congruential pseudo-random number generator (25173·s+13849) mod 2¹⁶ when started at s=1. A383940

Numbers n such that φ(φ(n)) + σ(σ(n)) - φ(σ(n)) - σ(φ(n)) = σ(n). A66946

Expansion of (1/x) * Series_Reversion( x / (1 + x⁴ * (1 + x)²) ). A389130

McKay-Thompson series of class 12C for the Monster group. A58206

Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 96. A31594

a(n) = smallest number that is the sum of 2n - 1, 2n + 1, and 2n + 3 consecutive primes. A288172

The positive odd numbers·such that x = c² - y and +-x = a +- y, where (a,b,c) is a primitive Pythagorean triple (PPT), a is odd and y is an even positive integer. A357535