Properties of the Number 21843

Twenty-One Thousand Eight Hundred Forty-Three

Basics

Value: 21842 → 21843 → 21844

Parity: odd

Prime: No

Previous Prime: 21841

Next Prime: 21851

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ³ × 809

Divisors: 1, 3, 9, 27, 809, 2427, 7281, 21843

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010101010011

Octal: 52523

Duodecimal: 10783

Hexadecimal: 5553

Square: 477116649

Square Root: 147.79377524104322

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

Number of partitions of n into parts of 3 kinds. A716

T(n,k)=Number of nXk 0..1 arrays with every element equal to 1, 2, 3 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. A302472

T(n,k) = Number of n X k 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero. A303254

First differences of A135351. A155980

Place n points in general position on each side of an equilateral triangle, and join every pair of the 3·n+3 boundary points by a chord; sequence gives number of edges in the resulting planar graph. A367119

Number of length 3 walks on an n-dimensional hypercubic lattice starting at the origin and staying in the nonnegative part. A64043

Numbers n such that (n+j) mod (2+j) = 1 for j from 0 to 6 and (n+7) mod 9 <> 1. A96025

Irregular triangle read by row: T(n,k), n>=1, k>=1, in which column k lists the numbers of A000716 multiplied by A000330(k), and the first element of column k is in row A000217(k). A252117

A generalized Jacobsthal sequence. A83944

a(n) = (2·2ⁿ+7*(-1)ⁿ)/3. A171382