Properties of the Number 21892

Twenty-One Thousand Eight Hundred Ninety-Two

Basics

Value: 21891 → 21892 → 21893

Parity: even

Prime: No

Previous Prime: 21881

Next Prime: 21893

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 2 ² × 13 × 421

Divisors: 1, 2, 4, 13, 26, 52, 421, 842, 1684, 5473

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010110000100

Octal: 52604

Duodecimal: 10804

Hexadecimal: 5584

Square: 479259664

Square Root: 147.95945390545344

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 binary vectors of length n containing no singletons. A6355

Number of base 4 n-digit numbers with adjacent digits differing by one or less. A126358

Layer counting sequence for hyperbolic tessellation by cuspidal triangles of angles (π/3,π/3,0) (this is the classical modular tessellation). A54886

Number of n-digit numbers N that do not end with 0 and are such that the reversal of N divides N but is different from N. A214927

Expansion of g.f. x*(1+x+x²)/(1-x-x²). A128588

a(0) = 1, then twice the Fibonacci sequence. A55389

Row sums of array T in A055818; twice the odd-indexed Fibonacci numbers after initial term. A55819

a(n) = 2·F(n-1) = L(n) - F(n), where F(n) and L(n) are Fibonacci and Lucas numbers respectively. A118658

Expansion of 2·x*(1 - x)/(1 - 3·x + x²). A52995

Numbers with two representations as the sum of two Fibonacci numbers. A78642