Properties of the Number 20836

Twenty Thousand Eight Hundred Thirty-Six

Basics

Value: 20835 → 20836 → 20837

Parity: even

Prime: No

Previous Prime: 20809

Next Prime: 20849

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ² × 5209

Divisors: 1, 2, 4, 5209, 10418, 20836

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000101100100

Octal: 50544

Duodecimal: 10084

Hexadecimal: 5164

Square: 434138896

Square Root: 144.34680460612904

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

Numbers m such that the decimal number concat(8,m) is a square. A273363

T(n,k)=3X3X3 triangular graph without horizontal edges coloring a rectangular array: number of nXk 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph. A223352

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

G.f.: ∑_k>=1 (k² * x^k² / ∏_j=1..k (1 - x^j)). A333141

Sum of the areas of the Durfee squares of all partitions of n. A116503

Number of multisets of exactly two partitions of positive integers into distinct parts with total sum of parts equal to n. A320787

3 X 3 X 3 triangular graph without horizontal edges coloring a rectangular array: number of n X 3 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph. A223347

3 X 3 X 3 triangular graph without horizontal edges coloring a rectangular array: number of n X 4 0..5 arrays where 0..5 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph. A223348

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 777", based on the 5-celled von Neumann neighborhood. A273532

a(n) = 3·binomial(n,4) - 6·binomial(n,3) + 4·binomial(n,2) - 2. A335694