Properties of the Number 21420

Twenty-One Thousand Four Hundred Twenty

Basics

Value: 21419 → 21420 → 21421

Parity: even

Prime: No

Previous Prime: 21419

Next Prime: 21433

Digit Sum: 9

Digital Root: 9

Palindrome: No

Factorization: 2 ² × 3 ² × 5 × 7 × 17

Divisors: 1, 2, 3, 4, 5, 6, 7, 9, 10, 12

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001110101100

Octal: 51654

Duodecimal: 10490

Hexadecimal: 53ac

Square: 458816400

Square Root: 146.3557310118056

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

a(n) = n*(n+1)*(n+2)/2. A27480

Pointwise product of the arithmetic derivative and the primorial base exp-function. A358669

Rectangular table, read by antidiagonals, where the g.f. of row n, R(x,n), satisfies: R(x,n) = 1 + (n+1)*x·R(x,n+1)² for n>=0. A128570

Row 4 of table A128570. A128574

Main diagonal of table A128570. A128578

a(n) = n*(n² - 1)/2. A135503

Array read by antidiagonals: A(n,k) is the number of unsensed planar maps with n vertices and k faces, n >= 1, k >= 1. A277741

The least positive integer that has exactly n different representations as Brazilian number. A284758

Numbers that are the sum of four third powers in six or more ways. A345148

Numbers that are the sum of four third powers in exactly six ways. A345149