Properties of the Number 21504

Twenty-One Thousand Five Hundred Four

Basics

Value: 21503 → 21504 → 21505

Parity: even

Prime: No

Previous Prime: 21503

Next Prime: 21517

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 ¹⁰ × 3 × 7

Divisors: 1, 2, 3, 4, 6, 7, 8, 12, 14, 16

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010000000000

Octal: 52000

Duodecimal: 10540

Hexadecimal: 5400

Square: 462422016

Square Root: 146.64242223858687

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

Expansion of g.f. (1+2·x)/(1-2·x)². A14480

3-fold convolution of A000302 (powers of 4). A38845

12-almost primes (generalization of semiprimes). A69273

Triangle whose (i,j)-th entry is binomial(i,j)*4^i-j. A38231

Numbers k such that ∑_j p_j = ∑_j e_j where ∏_j p_j^e_j is the prime factorization of k. A54411

a(n) = ((3·n)!/n!²)*(γ(1+n/2)/γ(1+3n/2)). A91527

a(n) = 21·2ⁿ. A175805

Consider the Post tag system defined in A284116; a(n) = number of binary words of length n which terminate at the empty word. A289670

The ED1 array read by antidiagonals. A167546

Triangle read by rows: T(n,m) (n >= m >= 1) = number of chambers (or regions) formed by drawing the line segments connecting any two of the (n+1) X (m+1) lattice points in an n X m lattice polygon. A288187