Properties of the Number 20591

Twenty Thousand Five Hundred Ninety-One

Basics

Value: 20590 → 20591 → 20592

Parity: odd

Prime: No

Previous Prime: 20563

Next Prime: 20593

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 59 × 349

Divisors: 1, 59, 349, 20591

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000001101111

Octal: 50157

Duodecimal: BABB

Hexadecimal: 506f

Square: 423989281

Square Root: 143.49564453320525

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

Odd composite integers m such that A014448(m) == 4 (mod m). A335670

Odd composite integers m such that A052918(m-J(m,29)) == 0 (mod m) and gcd(m,29)=1, where J(m,29) is the Jacobi symbol. A340095

Square array A(n,k), n>=0, k>=0, read by antidiagonals, where A(0,k) = 1 and A(n,k) = ∑_j=0..n-1 k^j * binomial(n-1,j) * A(j,k) for n > 0. A306245

Pseudoprimes to base 17. A20145

Odd composite integers m such that U(m)² == 1 (mod m) and V(m) == 4 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=4 and b=-1, respectively. A337627

Riordan array ( (1/(1-x))^m , x·A000108(x) ), m =4. A185945

Odd composite integers m such that A000032(3·m-J(m,5)) == 3·J(m,5) (mod m), where J(m,5) is the Jacobi symbol. A339724

Odd composite integers m such that A000045(3·m-J(m,5)) == 1 (mod m), where J(m,5) is the Jacobi symbol. A340235

Pseudoprimes to base 60. A20188

Pseudoprimes to base 66. A20194