Properties of the Number 21123

Twenty-One Thousand One Hundred Twenty-Three

Basics

Value: 21122 → 21123 → 21124

Parity: odd

Prime: No

Previous Prime: 21121

Next Prime: 21139

Digit Sum: 9

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 2347

Divisors: 1, 3, 9, 2347, 7041, 21123

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001010000011

Octal: 51203

Duodecimal: 10283

Hexadecimal: 5283

Square: 446181129

Square Root: 145.3375381654719

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

Sum of 1-bits between the most and least significant bits summed for all primes in range ]2ⁿ,2ⁿ⁺¹]. A95298

Numbers of the form HMMSS with primes H < 24 and MM, SS < 60, for which the number of seconds after midnight, 3600·H+60·MM+SS, is also prime. A295011

Starts of runs of 3 consecutive numbers that have an equal number of even and odd exponents in their prime factorization (A187039). A348077

Number of partitions of n with nine parts in which no part occurs more than twice. A320597

Number of nonnegative integer arrays of length n+2·5-2 with new values introduced in order 0 upwards and every value appearing only in runs of at least 5. A211697

Number of permutations of the prime indices of n with at least one non-singleton run, or non-separations. A336107

Number of (1,2,3)-matching permutations of the prime indices of n. A335520

a(n) = (2ⁿ-1)² - 2. A93112

Number of compositions of n² with parts <= n, such that each element of [n] is used at least once. A332721

Number of (2,1,2)-matching permutations of the prime indices of n. A335453