Properties of the Number 21166

Twenty-One Thousand One Hundred Sixty-Six

Basics

Value: 21165 → 21166 → 21167

Parity: even

Prime: No

Previous Prime: 21163

Next Prime: 21169

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 2 × 19 × 557

Divisors: 1, 2, 19, 38, 557, 1114, 10583, 21166

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001010101110

Octal: 51256

Duodecimal: 102BA

Hexadecimal: 52ae

Square: 447999556

Square Root: 145.48539445593843

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

T(n,k) = Number of n X k binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or nw-se diagonally. A228285

floor(r·a(n-1)) + floor(r·a(n-2)), where r = 3/2, a(0) = 1, a(1) = 1. A275862

a(n) = 15·n² - 13·n. A263226

Numbers k such that 24·k-1 has at least three factors 7 and the partition function evaluated at k has at least the same number of factors 7 as 24·k-1. A340957

Number of n-node rooted trees of height 6. A393

Numbers k such that 70·R_k + 3, where R_k = 11...1 is the repunit (A002275) of length k. A56689

Output of the linear congruential pseudo-random number generator used in function rand() as described in Kernighan and Ritchie, when seeded with 0. A96554

Number of nX5 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or nw-se diagonally. A228280

Number of nX6 binary arrays with top left value 1 and no two ones adjacent horizontally, vertically or nw-se diagonally. A228281

The number of tilings of a 7 X (3n) floor with 1 X 3 trominoes. A236578