Properties of the Number 21813

Twenty-One Thousand Eight Hundred Thirteen

Basics

Value: 21812 → 21813 → 21814

Parity: odd

Prime: No

Previous Prime: 21803

Next Prime: 21817

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 11 × 661

Divisors: 1, 3, 11, 33, 661, 1983, 7271, 21813

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010100110101

Octal: 52465

Duodecimal: 10759

Hexadecimal: 5535

Square: 475806969

Square Root: 147.6922475961416

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

Numbers n such that 11n is a partition number. A225323

Number of partitions of 5n such that cn(1,5) = cn(4,5) <= cn(0,5) <= cn(2,5) = cn(3,5). A36881

Coefficients of the C-Rogers mod 14 identity. A105782

Number of Barlow packings with group P3(bar)m1(SO) that repeat after 2n-1 layers. A11950

Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-1,0,1,2}. A79982

Smallest k>1 such that 10·k^5·2ⁿ+1 is prime. A381793

Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 98. A31596

Number of perfect rhythmic tilings of [0,4n-1] with quadruplets. A261517

Number of perfect rhythmic tilings of [0,3n-1] with triples. A261516

Decimal expansion of 1/809. A21813