Properties of the Number 21542

Twenty-One Thousand Five Hundred Forty-Two

Basics

Value: 21541 → 21542 → 21543

Parity: even

Prime: No

Previous Prime: 21529

Next Prime: 21557

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 2 × 10771

Divisors: 1, 2, 10771, 21542

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010000100110

Octal: 52046

Duodecimal: 10572

Hexadecimal: 5426

Square: 464057764

Square Root: 146.77193192160414

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) is the largest number whose sixth power is an n-digit sixth power which has the maximum sum of digits (A373994(n)). A380193

Least k such that prime(n) is the smallest prime p for which k² + p² is also prime, or 0 if none. A263466

Integers n > 10553 such that the 'Reverse and Add!' trajectory of n joins the trajectory of 10553. A63061

Semiprimes (A001358) whose digit reversal is a pentagonal number (A000326). A115708

Coordination sequence for MgCu2, Cu position. A9930

Number of permutations of length n that avoid the patterns 321, 1342, 4123. A116714

Number of n X 2 0..2 arrays with no element unequal to a strict majority of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. A279851

Alternating sum of the numbers in the trajectory of n for the 3x+1 problem. A386437

Decimal expansion of 1/538. A21542