Properties of the Number 21126

Twenty-One Thousand One Hundred Twenty-Six

Basics

Value: 21125 → 21126 → 21127

Parity: even

Prime: No

Previous Prime: 21121

Next Prime: 21139

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 × 3 × 7 × 503

Divisors: 1, 2, 3, 6, 7, 14, 21, 42, 503, 1006

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001010000110

Octal: 51206

Duodecimal: 10286

Hexadecimal: 5286

Square: 446307876

Square Root: 145.34785860135676

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 3 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing. A86113

a(n) is the concatenation of n and 6n. A9440

T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the number of clockwise edge increases in every 2X2 subblock equal to two. A205836

Expansion of ∑_n>=0 (qⁿ / ∏_k=1..n+5 (1 - q^k)). A35301

Numbers n such that 30n+{11, 13, 17, 19, 23} are 5 consecutive primes. A182279

Number of n X 2 0..1 arrays with rows, columns and antidiagonals unimodal and diagonals nondecreasing. A223764

McKay-Thompson series of class 14A for the Monster group with a(0) = 1. A134782

G.f.: A(x) = ∑_n>=0 (-1)ⁿ * (1 -x -2ⁿ*x²)^-1 * log(1 -x -2ⁿ*x²)ⁿ / n!. A136509

Shallit sequence S(3,13), a(n)=[ a(n-1)²/a(n-2)+1 ]. A10921

McKay-Thompson series of class 14A for Monster. A58497