Properties of the Number 21387

Twenty-One Thousand Three Hundred Eighty-Seven

Basics

Value: 21386 → 21387 → 21388

Parity: odd

Prime: No

Previous Prime: 21383

Next Prime: 21391

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 7129

Divisors: 1, 3, 7129, 21387

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001110001011

Octal: 51613

Duodecimal: 10463

Hexadecimal: 538b

Square: 457403769

Square Root: 146.24294854795565

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

Stack polyominoes with square core. A188674

Number of integer partitions of n whose parts do not have choosable sets of integer partitions. A387134

a(n) = a(n-1) + a(floor(n/2)) + a(ceiling(n/2)). A131205

a(1) = 3; a(n) = smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. A83993

a(n) = 74·n² + 1. A158742

Number of spiro bicyclic skeletons with n carbon atoms. A107278

Least j such that 6·p(j)*M(n)-1 is prime with p(j)=j-th prime and M(n) = Mersenne prime. A157333

Number of hypoplactic classes of 4-parking functions of length n. A243676

Decimal expansion of 1/383. A21387

Numbers k such that A051378(k) > 2·k and A333926(k) <= 2·k. A349284