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Properties of the Number 21030

Twenty-One Thousand Thirty

Basics

Value: 21029 → 21030 → 21031

Parity: even

Prime: No

Previous Prime: 21023

Next Prime: 21031

Digit Sum: 6

Digital Root: 6

Palindrome: No

Factorization: 2 × 3 × 5 × 701

Divisors: 1, 2, 3, 5, 6, 10, 15, 30, 701, 1402

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001000100110

Octal: 51046

Duodecimal: 10206

Hexadecimal: 5226

Square: 442260900

Square Root: 145.01724035437994

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) = Z(Sm; σ[1](n), σ[2](n),..., σ[m](n)) where Z(Sm; x1,x2,...,xm) is the cycle index of the symmetric group Sm and σ[k](n) is the sum of k-th powers of divisors of n; m=3. A68020
a(n) = 25·n2 + 5. A158445
Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 58. A31736
Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,7. A64240
Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,21. A64247
a(1) = 5; a(n+1) = a(n)-th nonprime, where nonprimes begin at 0. A25001
Decimal expansion of 1/26. A21030
Number of (n+1)X5 0..2 arrays with every 2 X 2 subblock having the same number of clockwise edge increases as its horizontal neighbors and no 2 X 2 subblock having the same number of counterclockwise edge increases as its vertical neighbors. A205732
Number of ways to write 12·n + 5 as 2·x2 + 5·y2 + 9·z2 + x·y*z, where x, y and z are nonnegative integers. A352356