Properties of the Number 71991

Seventy-One Thousand Nine Hundred Ninety-One

Basics

Value: 71990 → 71991 → 71992

Parity: odd

Prime: No

Previous Prime: 71987

Next Prime: 71993

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 19 × 421

Divisors: 1, 3, 9, 19, 57, 171, 421, 1263, 3789, 7999

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10001100100110111

Octal: 214467

Duodecimal: 357B3

Hexadecimal: 11937

Square: 5182704081

Square Root: 268.31138626603234

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 strings of numbers x(i=1..n) in 0..2 with sum i²*x(i) equal to n²*2. A183946

Trajectory of 1 under map n->13n+1 if n odd, n->n/2 if n even. A33964

a(1) = a(2) = 1; a(n) = a(floor(n/3)) + a(n - floor(n/3)). A71991