Properties of the Number 21668

Twenty-One Thousand Six Hundred Sixty-Eight

Basics

Value: 21667 → 21668 → 21669

Parity: even

Prime: No

Previous Prime: 21661

Next Prime: 21673

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 ² × 5417

Divisors: 1, 2, 4, 5417, 10834, 21668

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010010100100

Octal: 52244

Duodecimal: 10658

Hexadecimal: 54a4

Square: 469502224

Square Root: 147.20054347725758

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

Absolute discriminants of complex quadratic fields with 3-class group of elementary abelian type (3,3) of rank 2. A242863

Absolute discriminants of complex quadratic fields with 3-class rank 2. A242862

Absolute discriminants of complex quadratic fields with 3-class group of type (3,3) and Hilbert 3-class field tower of exact length 3, except for the cases mentioned in the COMMENTS. A242878

Minimal absolute discriminants a(n) of complex quadratic fields with 3-class group of type (3,3), 3-principalization type H.4 (2122), second 3-class group G of even nilpotency class cl(G)=2(n+3), and 3-class tower of unknown length at least 3. A247694

Number of slanted n X 4 (i=1..n) X (j=i..4+i-1) 1..4 arrays with all 1s connected, all 2s connected, all 3s connected, all 4s connected, 1 in the upper left corner, 2 in the upper right corner, 3 in the lower left corner, 4 in the lower right corner, and with no element having more than 3 neighbors with the same value. A165381

Total length squared of longest runs of 1's in all bitstrings of length n. A334833

Consecutive states of the linear congruential pseudo-random number generator (1291·s + 4621) mod 21870 when started at s=1. A385337

The successive approximations up to 2ⁿ for 2-adic integer 9^1/3. A322999

Number of nX4 0..1 arrays with every element unequal to 0, 2, 3, 4 or 7 king-move adjacent elements, with upper left element zero. A304890

Number of genus 2 partitions of the set [3n] into n blocks of length 3. A371251