Properties of the Number 11981

Eleven Thousand Nine Hundred Eighty-One

Basics

Value: 11980 → 11981 → 11982

Parity: odd

Prime: Yes

Previous Prime: 11971

Next Prime: 11987

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 11981

Divisors: 1, 11981

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10111011001101

Octal: 27315

Duodecimal: 6B25

Hexadecimal: 2ecd

Square: 143544361

Square Root: 109.45775440780794

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 vertices in a regular drawing of the complete bipartite graph K_n,n. A331755

Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + b(n-2), where a(0) = 1, a(1) = 3, b(0) = 2, b(1) = 4. A294414

Least prime in A031924 (lesser of 6-twins) such that the distance to the next 6-twin is 2·n. A52352

Beginnings of maximal chains of primes with three members (two links). A152866

Primes having only {1, 8, 9} as digits. A385783

First primes of arithmetic progressions of 5 primes each with the common difference 30. A227281

Primes p such that (p³² + 1)/2 is prime. A341224

Primes p2 such that p1² + p2³ is an average of twin primes and p1 < p2 are consecutive primes. A138716

Number of ordered triples (w,x,y) with all terms in {1,...,n} and w²>x²+y². A211637

Number of partitions of n into parts but with two kinds of parts of sizes 1 to 10. A103929