Properties of the Number 21431

Twenty-One Thousand Four Hundred Thirty-One

Basics

Value: 21430 → 21431 → 21432

Parity: odd

Prime: No

Previous Prime: 21419

Next Prime: 21433

Digit Sum: 11

Digital Root: 2

Palindrome: No

Factorization: 29 × 739

Divisors: 1, 29, 739, 21431

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101001110110111

Octal: 51667

Duodecimal: 1049B

Hexadecimal: 53b7

Square: 459287761

Square Root: 146.3933058578841

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 partitions p of n such that the number of distinct parts is not a part and max(p) - min(p) is a part. A241388

Odd semiprimes k = p·q such that k = A325820(p,q), with p, q primes > 3, and A325820 is the carryless base-3 multiplication. A391331

a(n) = ∑_{k=0..floor(n/3)} Stirling2(n - 2·k,n - 3·k). A357925

Analog of A006684 for the 7x+1 problem (cf. A133421). A133425

Number of n X 2 0..1 arrays with each 1 adjacent to 1 or 3 king-move neighboring 1s. A295937

a(1) = 1; a(n) = ∑_k=1..n-1 a(n-k) * ∑_d∣k a(d)*a(k/d). A307816

Decimal expansion of 1/427. A21431