Properties of the Number 12780

Twelve Thousand Seven Hundred Eighty

Basics

Value: 12779 → 12780 → 12781

Parity: even

Prime: No

Previous Prime: 12763

Next Prime: 12781

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ² × 3 ² × 5 × 71

Divisors: 1, 2, 3, 4, 5, 6, 9, 10, 12, 15

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11000111101100

Octal: 30754

Duodecimal: 7490

Hexadecimal: 31ec

Square: 163328400

Square Root: 113.04866208850063

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 of n such that (number of distinct parts) = maximal multiplicity of the parts. A239964

Numbers k which have a factorization k = f1·f2*...*fr where the digits of {k, f1, f2, ..., fr} together give 0,1,...,9 exactly once. A370970

5 times hexagonal numbers: 5·n*(2·n-1). A152745

a(n) = n*(4·n² - 3·n + 5)/6. A174723

Number of rucksack compositions of n: every distinct partial run has a different sum. A354580

Composite numbers with properties that its digits (which may appear with multiplicity) may not appear in any of its factors (wherein the digits may also appear with multiplicity) and the combined digits of the product and the factors must have at least one of each of the ten digits. A370972

Square array T(k,n) by antidiagonals, where T(k,n) is number of ways of placing n identifiable nonnegative intervals with a total of exactly k starting and/or finishing points. A59515

a(n) = (sum of first n primes) * n. A167214

T(n,k)=Number of (n+2)X(k+2) 0..2 arrays with no 2X2 subblock sum equal to any diagonal or antidiagonal neighbor 2X2 subblock sum. A187600

Numbers k such that k*(k+1)-1 and k*(k+1)+1 are twin primes and k*(k+3)-1 and k*(k+3)+1 are also twin primes. A138303