Properties of the Number 20838

Twenty Thousand Eight Hundred Thirty-Eight

Basics

Value: 20837 → 20838 → 20839

Parity: even

Prime: No

Previous Prime: 20809

Next Prime: 20849

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 2 × 3 × 23 × 151

Divisors: 1, 2, 3, 6, 23, 46, 69, 138, 151, 302

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000101100110

Octal: 50546

Duodecimal: 10086

Hexadecimal: 5166

Square: 434222244

Square Root: 144.35373219975992

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

G.f. satisfies A(x) = 1 + x·A(x)⁴*(1 + x·A(x)⁴). A365183

Relative of Hofstadter Q-sequence: a(n) = max(0, n+20830) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 0. A283887

Numbers k such that k² contains only digits {2,3,4}. A53916

When squared gives number composed just of the digits 1, 2, 3, 4. A61677

Numbers k such that k and k² use only the digits 0, 2, 3, 4 and 8. A136885

Number of n X 3 0..2 arrays with every 1 immediately preceded by 0 to the left or above, no 0 immediately preceded by a 0, and every 2 immediately preceded by 0 1 to the left or above. A203176

a(n) = n-th π-based antiderivative of 7. A259168

Array of coefficients A(n,k) of the formal power series P(n,x) read by upwards antidiagonals, where P(n,x) = ∑_k>=0 A(n,k)*x^k = 1+x·P(n,x)^1·n+x²*P(n,x)^2·n for n >= 0. A261440

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 222", based on the 5-celled von Neumann neighborhood. A270940

Number of n X n arrays of squares of integers with every 2X2 subblock summing to 18. A159219