Properties of the Number 21686

Twenty-One Thousand Six Hundred Eighty-Six

Basics

Value: 21685 → 21686 → 21687

Parity: even

Prime: No

Previous Prime: 21683

Next Prime: 21701

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 × 7 × 1549

Divisors: 1, 2, 7, 14, 1549, 3098, 10843, 21686

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010010110110

Octal: 52266

Duodecimal: 10672

Hexadecimal: 54b6

Square: 470282596

Square Root: 147.26167186338745

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 integer partitions of n that can be partitioned into sets with distinct sums. A381992

a(1) = a(2) = 2; a(n) = a(n-1) + gpf(a(n-2)), where gpf is greatest prime factor. A258125

Number of walks within N³ (the first octant of Z³) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (0, -1, 1), (0, 0, 1), (1, 0, 0), (1, 1, -1)}. A150154

a(n) = ceiling(A003269(n)/2). A173674

Decimal expansion of 1/682. A21686

Number of (n+2)X(4+2) 0..3 arrays with every 3X3 subblock row and column sum not 1 3 6 or 8 and every diagonal and antidiagonal sum 1 3 6 or 8. A252049