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Properties of the Number 21790

Twenty-One Thousand Seven Hundred Ninety

Basics

Value: 21789 → 21790 → 21791

Parity: even

Prime: No

Previous Prime: 21787

Next Prime: 21799

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 × 5 × 2179

Divisors: 1, 2, 5, 10, 2179, 4358, 10895, 21790

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010100011110

Octal: 52436

Duodecimal: 1073A

Hexadecimal: 551e

Square: 474804100

Square Root: 147.61436244485157

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 that are the sum of one or more consecutive squares in more than one way. A130052
T(n,k) = Number of n X k 0..1 arrays with the number of 1's horizontally or vertically adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero. A284165
Numbers that are sums of 2 or more consecutive squares in more than 1 way. A62681
Numbers n such that n through n+5 have the same number of distinct prime factors. A45934
G.f.: ∑k>=0 xk*(k+1/2) / ∏j=1..k (1 - x2·j-1)2. A376624
Number of arrays of median of three adjacent elements of some length-5 0..n array, with no adjacent equal elements in the latter. A229013
Numbers that can be written as the sum of four or more consecutive squares in more than one way. A307937
Triangle related to generalized Euler numbers of type 2n (A005799). A88990
Number of n X 3 0..1 arrays with the number of 1's horizontally or vertically adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero. A284160
Number of n X 6 0..1 arrays with the number of 1's horizontally or vertically adjacent to some 0 equal to the number of 0's adjacent to some 1, with top left element zero. A284163