Properties of the Number 20845

Twenty Thousand Eight Hundred Forty-Five

Basics

Value: 20844 → 20845 → 20846

Parity: odd

Prime: No

Previous Prime: 20809

Next Prime: 20849

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 5 × 11 × 379

Divisors: 1, 5, 11, 55, 379, 1895, 4169, 20845

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000101101101

Octal: 50555

Duodecimal: 10091

Hexadecimal: 516d

Square: 434514025

Square Root: 144.37797615980077

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 partitions of n such that the least part occurs at least twice. A117989

a(n) = (2·n-1)*(n² -n +2)/2. A63488

Number of partitions of n where the difference between consecutive parts is at most 8. A238868

a(n) = a(n-1) + floor(a(n-2)/2) with a(0)=1, a(1)=2. A64324

Composite numbers equal to the sum of the prime factors, with multiplicity, of the previous k numbers, for some k. A257525

Number of partitions of n into parts not of the form 13k, 13k+4 or 13k-4. Also number of partitions with at most 3 parts of size 1 and differences between parts at distance 5 are greater than 1. A35952

Number of partitions of n such that m(greatest part) <= m(1), where m = multiplicity. A240077

Relative of Hofstadter Q-sequence: a(n) = max(0, n+20830) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) + a(n-a(n-3)) for n > 0. A283887

Ulam's spiral (WSW spoke). A143854

Unicode codes for the Han digits. A61745