Properties of the Number 20995

Twenty Thousand Nine Hundred Ninety-Five

Basics

Value: 20994 → 20995 → 20996

Parity: odd

Prime: No

Previous Prime: 20983

Next Prime: 21001

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 5 × 13 × 17 × 19

Divisors: 1, 5, 13, 17, 19, 65, 85, 95, 221, 247

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001000000011

Octal: 51003

Duodecimal: 10197

Hexadecimal: 5203

Square: 440790025

Square Root: 144.8965147959053

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 whose multiset of multiplicities has integer mean. A360069

The product of primes <= n that are strongly prime to n. A181836

T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum prime and every diagonal and antidiagonal sum nonprime. A251950

Expansion of sqrt( (1+x + sqrt(1-18·x+x²)) / (2*(1-18·x+x²)) ). A243946

Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of sqrt((1+(k-4)*x+sqrt(1-2*(k+4)*x+((k-4)*x)²)) / (2 * (1-2*(k+4)*x+((k-4)*x)²))). A337389

Numbers that are the sum of five fourth powers in three or more ways. A344243

Numbers that are the sum of five fourth powers in exactly four ways. A344355

Numbers that are the sum of five fourth powers in four or more ways. A344354

Heinz numbers of knapsack partitions such that no addition of one part up to the maximum is knapsack. A326018

a(n) = product of those positive integers which are coprime to both n and n+1 and which are <= n. A124740