Properties of the Number 20663

Twenty Thousand Six Hundred Sixty-Three

Basics

Value: 20662 → 20663 → 20664

Parity: odd

Prime: Yes

Previous Prime: 20641

Next Prime: 20681

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 20663

Divisors: 1, 20663

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000010110111

Octal: 50267

Duodecimal: BB5B

Hexadecimal: 50b7

Square: 426959569

Square Root: 143.7463043003193

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 compositions of n with all adjacent parts (x, y) satisfying x < 2y and y <= 2x. A342338

a(n) = numerator of sum of reciprocals of the terms of the continued fraction for H(n) = ∑_k=1..n 1/k. A112286

T(n,k)=Number of nXk 0..2 arrays with every element equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) (1,-1) or (1,0) both plus 1 mod 3 and minus 1 mod 3, with new values introduced in order 0..2. A277788

Primes of the form 3·m² - 4. A201716

Primes which are the sum of three distinct positive cubes in two or more distinct ways. A180088

a(n)² is the start of the first occurrence of n consecutive perfect powers, all of which are squares with exponents equal to 2 (A111245). A340663

Primes that remain prime through 3 iterations of function f(x) = 5x + 4. A23284

a(n) is smallest safe prime (A005385) such that a(n) + 12·n is the next safe prime, i.e., x = (a(n) - 1)/2 and x + 6·n are closest Sophie Germain primes. A59327

Prime numbers, isolated from neighboring primes by >16. A137875

Primes congruent to 13 mod 59. A142740