Properties of the Number 12987

Twelve Thousand Nine Hundred Eighty-Seven

Basics

Value: 12986 → 12987 → 12988

Parity: odd

Prime: No

Previous Prime: 12983

Next Prime: 13001

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ³ × 13 × 37

Divisors: 1, 3, 9, 13, 27, 37, 39, 111, 117, 333

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 11001010111011

Octal: 31273

Duodecimal: 7623

Hexadecimal: 32bb

Square: 168662169

Square Root: 113.96051947933547

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) = A047080(2·n+1, n+2). A47088

-9-Knödel numbers. A225513

Numbers k such that φ(k) is a perfect 5th power. A78165

T(n,k) = Number of (n+2) X (k+2) 0..2 arrays with every consecutive three elements in every row and column having exactly two distinct values, and new values 0 upwards introduced in row major order. A253035

Number of free poly-IH19-tiles (holes allowed) with n cells. A197552

Indices of square numbers which are also heptagonal. A46196

Numbers k such that A011772(k) > A344878(k) and A011772(k) is a divisor of A344875(k). A344595

a(n) = n*(19·n - 1)/2. A22276

Sequence A001033 gives the numbers n such that the sum of the squares of n consecutive odd numbers x² + (x+2)² + ... +(x+2n-2)² = k² for some integer k. For each n, this sequence gives the least value of k. A56132

Rectangular array read by antidiagonals: a(n, k) is the number of ways to put k labeled objects into n labeled boxes so that there are no boxes with exactly one object (n, k >= 1). A131103