Properties of the Number 13781

Thirteen Thousand Seven Hundred Eighty-One

Basics

Value: 13780 → 13781 → 13782

Parity: odd

Prime: Yes

Previous Prime: 13763

Next Prime: 13789

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 13781

Divisors: 1, 13781

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11010111010101

Octal: 32725

Duodecimal: 7B85

Hexadecimal: 35d5

Square: 189915961

Square Root: 117.39250401963491

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

Primes of the form 5k² + 5k + 1. A90562

Primes such that the sum of the predecessor and successor primes is divisible by 41. A113157

Primes p such that the multiplicative order of 2 modulo p is (p-1)/5. A1135

a(n) is the n-th term of sequence A_n, ignoring the offset, or -1 if A_n has fewer than n terms. A91967

Primes p such that p+1, p+2 and p+3 have equal number of divisors. A119711

Expansion of ∏_k>=1 ((1 + x^2·k) / (1 - x^k))^k. A285462

Primes p such that p+1, p+2, p+3 and p+4 have equal number of divisors. A119728

Primes p such that p+1, p+2, p+3, p+4 and p+5 have equal number of divisors. A119730

Triangle read by rows: T(n,k) is the number of embeddings on the sphere of 2-connected homeomorphically irreducible planar graphs with n nodes and k faces, k=4..2n-4. A378075

Incorrect version of A091967. A31135