Properties of the Number 66681

Sixty-Six Thousand Six Hundred Eighty-One

Basics

Value: 66680 → 66681 → 66682

Parity: odd

Prime: No

Previous Prime: 66653

Next Prime: 66683

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 31 × 239

Divisors: 1, 3, 9, 31, 93, 239, 279, 717, 2151, 7409

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10000010001111001

Octal: 202171

Duodecimal: 32709

Hexadecimal: 10479

Square: 4446355761

Square Root: 258.22664463606384

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

Berend Jan van der Zwaag's conjectured complete list of numbers that start different "expanding periodic loops" under the mapping described in A053392 and A060630. A103117

Numbers k such that the k-th triangular number contains only digits {1,2,3}. A119098

Number of 2 X 2 matrices having all terms in {-n,...,0,...,n} and nonnegative determinant. A211147

G.f. A(x) satisfies (3·A(x⁹)/A(x) - 1)³ = 9·A(x³)³/A(x)³ - 1 - 9·x. A376528

Numbers that can be written in exactly two different ways in the form described by A387302. A387898

Badly sieved numbers (A066680) which are not primes. A66681