Properties of the Number 12640

Twelve Thousand Six Hundred Forty

Basics

Value: 12639 → 12640 → 12641

Parity: even

Prime: No

Previous Prime: 12637

Next Prime: 12641

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 2 ⁵ × 5 × 79

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 32, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11000101100000

Octal: 30540

Duodecimal: 7394

Hexadecimal: 3160

Square: 159769600

Square Root: 112.42775458044157

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) = ∑_k=0..n T(k) where T(n) are the tribonacci numbers A000073. A8937

4 times hexagonal numbers: a(n) = 4·n*(2·n-1). A85250

List of different composites in Pascal-like triangles with index of asymmetry y = 2 and index of obliquity z = 0 or z = 1. A141066

Numbers k such that the largest unitary divisor of σ(k) that is coprime with A003961(k) is also a unitary divisor of k. A351551

Number of possible queen moves on an n X n chessboard. A35005

a(n) = prime(prime(prime(A028815(n) - 1) - 1) - 1) - 1. A141133

Numbers k such that the odd part of σ(σ(k)) is equal to the odd part of σ(k). A353365

a(n) = 2·n³ - 3·n² + 5. A152064

Define the generalized Pisot sequence T(a(0),a(1)) by: a(n+2) is the greatest integer such that a(n+2)/a(n+1) < a(n+1)/a(n). This is T(4,8). A18921

For any k, the cumulative sum a(1) + a(2) + a(3) + ... + a(k) shares at least five digits with a(k). Lexicographically first sequence of positive integers without duplicate terms having this property. A326640