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Properties of the Number 20664

Twenty Thousand Six Hundred Sixty-Four

Basics

Value: 20663 → 20664 → 20665

Parity: even

Prime: No

Previous Prime: 20663

Next Prime: 20681

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 3 × 3 2 × 7 × 41

Divisors: 1, 2, 3, 4, 6, 7, 8, 9, 12, 14

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000010111000

Octal: 50270

Duodecimal: BB60

Hexadecimal: 50b8

Square: 427000896

Square Root: 143.74978260853126

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

Numbers k such that k6 + 1091 is prime. A66386
Numbers n such that there exists an x≠n that makes {x,x,n} an amicable multiset. A259303
Numbers that belong to at least one amicable multiset. A259307
Integers k such that there are i groups of order k+i up to isomorphism, for i=1,2,3. A373649
At stage 1, start with a unit equilateral equiangular triangle. At each successive stage add 3*(n-1) new triangles around outside with edge-to-edge contacts. Sequence gives number of triangles (regardless of size) at n-th stage. A64412
Table, read by antidiagonals, in which the n-th row comprises A214206(n) 0 followed by a second-order recursive series G in which each product G(i)*G(i+1) lies in the same row of A001477 (interpreted as a square array). A182431
Numbers k such that A344753(k) is a multiple of A048250(k), and k is a multiple of A344753(k)/A048250(k). A344755
Integers k such that there are i groups of order k+i up to isomorphism, for i=1,2,3,4. A373650
Sum of the parts of all partitions of n-1 plus the sum of the emergent parts of the partitions of n. A182707
Expansion of 1/((1-x)*(1+x+x2+2·x3)). A77909