Properties of the Number 65781

Sixty-Five Thousand Seven Hundred Eighty-One

Basics

Value: 65780 → 65781 → 65782

Parity: odd

Prime: No

Previous Prime: 65777

Next Prime: 65789

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 7309

Divisors: 1, 3, 9, 7309, 21927, 65781

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10000000011110101

Octal: 200365

Duodecimal: 32099

Hexadecimal: 100f5

Square: 4327139961

Square Root: 256.478069237898

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

G.f. A(x) = ∑_n=-oo..+oo xⁿ * (1 + xⁿ)^2·n. A260147

Sieve performed by successive iterations of steps where step m is: keep m terms, remove the next 3 and repeat; as m = 1,2,3,.. the remaining terms form this sequence. A112561

a(n) = binomial(n + 4, n - 1) + 1. A323228

a(1) = 25; for n > 1, a(n) is the smallest integer > 0 such that the concatenation a(n)a(n-1)...a(2)a(1) is a square. A65781