Properties of the Number 20559

Twenty Thousand Five Hundred Fifty-Nine

Basics

Value: 20558 → 20559 → 20560

Parity: odd

Prime: No

Previous Prime: 20551

Next Prime: 20563

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 7 × 11 × 89

Divisors: 1, 3, 7, 11, 21, 33, 77, 89, 231, 267

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101000001001111

Octal: 50117

Duodecimal: BA93

Hexadecimal: 504f

Square: 422672481

Square Root: 143.38409953687332

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 ways of writing n as the sum of 7 triangular numbers. A226252

Iccanobirt prime indices (1 of 15): Indices of prime numbers in A102111. A102131

Sum of the smallest parts of the partitions of 4n into 4 parts. A238702

Denominators of convergents to π by Farey fractions. A63673

Numbers of the form HMMSS with primes H < 24 and MM, SS < 60, for which the number of seconds after midnight, 3600·H+60·MM+SS, is also prime. A295011

a(n) = ∑_{k=0..floor(n/2)} binomial(n-k,k)^k+1 * n/(n-k). A181071

a(0)=a(1)=1, a(n) = least k > a(n-1) such that k·a(n-2) is a triangular number. A214961

A(n,k) is the sum of all compositions [c₁, c₂, ..., c_k] of n into k nonnegative parts encoded as ∏_i=1..k prime(i)^c_i; square array A(n,k), n>=0, k>=0, read by antidiagonals. A343751

Number of partitions of 1/n into 4 reciprocals of positive integers. A20327

a(n) = (2·n+1)*(7·n+1). A33572