Properties of the Number 12991

Twelve Thousand Nine Hundred Ninety-One

Basics

Value: 12990 → 12991 → 12992

Parity: odd

Prime: No

Previous Prime: 12983

Next Prime: 13001

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 11 × 1181

Divisors: 1, 11, 1181, 12991

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 11001010111111

Octal: 31277

Duodecimal: 7627

Hexadecimal: 32bf

Square: 168766081

Square Root: 113.97806806574675

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

Sums of six consecutive squares: a(n) = n² + (n+1)² + (n+2)² + (n+3)² + (n+4)² + (n+5)². A27865

Sum of the fifth largest parts in the partitions of n into 6 parts. A308869

Number of inequivalent convex lattice polygons containing n lattice points (including points on the boundary). A371917

Nonprime numbers with all divisors starting and ending with digit 1. A208261

Free polyominoes with 2n squares, having 180-degree rotational symmetry about a square mid-side. A234010

Records in A360519. A361107

Composite numbers k with its divisors having the property that the last digit of every divisor is the same as the first digit of the next divisor. A307858

Strong pseudoprimes to base 81. A20307

Composite numbers whose prime factors contain no digits other than 1 and 8. A36308

Solution of the complementary equation a(n) = 2·a(n-1) - a(n-2) + b(n-1) -2, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences. A294868