Properties of the Number 25781

Twenty-Five Thousand Seven Hundred Eighty-One

Basics

Value: 25780 → 25781 → 25782

Parity: odd

Prime: No

Previous Prime: 25771

Next Prime: 25793

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 7 × 29 × 127

Divisors: 1, 7, 29, 127, 203, 889, 3683, 25781

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 110010010110101

Octal: 62265

Duodecimal: 12B05

Hexadecimal: 64b5

Square: 664659961

Square Root: 160.56462873248267

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

a(n) = a(n-1) + ∑_k=0..n-4 a(k)*a(n-4-k), a(0) = 1. Generalized Catalan Numbers. A23426

Irregular array read by rows. a(n) is the largest element in the primitive Collatz-like 3x-k cycle associated with A226623(n). A226624

E.g.f.: ∏_k>=1 1 / (1 - x^k)^exp(-x/k). A346546

Number of 7-length words w over n-ary alphabet such that for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z. A213286

Erroneous version of A271811 (but for odd primes only). A271664

a(n) = Bell(n-1)*Motzkin(n). A290445

Number of n-length words w over 6-ary alphabet such that for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z. A213294

Number A(n,k) of n-length words w over a k-ary alphabet such that for every prefix z of w we have #(z,a_i) = 0 or #(z,a_i) >= #(z,a_j) for all j>i and #(z,a_i) counts the occurrences of the i-th letter in z; square array A(n,k), n>=0, k>=0, read by antidiagonals. A213276

Runs of consecutive numbers with the same number of divisors. A225756

Number of 3Xn arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and nonincreasing columns, 0..2 3Xn array. A219854