Properties of the Number 21847

Twenty-One Thousand Eight Hundred Forty-Seven

Basics

Value: 21846 → 21847 → 21848

Parity: odd

Prime: No

Previous Prime: 21841

Next Prime: 21851

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 7 × 3121

Divisors: 1, 7, 3121, 21847

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010101010111

Octal: 52527

Duodecimal: 10787

Hexadecimal: 5557

Square: 477291409

Square Root: 147.80730699123097

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 distinct quadratic residues mod 2ⁿ. A23105

Number of cyclic arrangements of S={1,2,...,n} such that the difference between any two neighbors is at most 3. A242525

a(n) = (5 + (-2)ⁿ)/3. A140966

a(n) = (4ⁿ + 5)/3. A163834

a(n) = (8·2ⁿ-5*(-1)ⁿ)/3. A83582

Jacobsthal numbers A001045 incremented by 2. A153643

O.g.f. satisfies: A(x) = ∑_n>=0 (n+4)ⁿ * xⁿ * A(n·x)ⁿ/n! * exp(-(n+4)*x·A(n·x)). A221413

a(n) = (2ⁿ + 3 - 7*(-1)ⁿ + 3·0ⁿ)/6; or a(0) = 0 and for n > 0, a(n) = A005578(n-1) - (-1)ⁿ. A135351

Decimal representation of the x-axis, from the origin to the right edge, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 14", based on the 5-celled von Neumann neighborhood. A277955

First differences of A130624. A130625