Properties of the Number 20835

Twenty Thousand Eight Hundred Thirty-Five

Basics

Value: 20834 → 20835 → 20836

Parity: odd

Prime: No

Previous Prime: 20809

Next Prime: 20849

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 × 463

Divisors: 1, 3, 5, 9, 15, 45, 463, 1389, 2315, 4167

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

8509 Try Today's Challenge

Representations

Binary: 101000101100011

Octal: 50543

Duodecimal: 10083

Hexadecimal: 5163

Square: 434097225

Square Root: 144.3433406846329

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

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

Solution (a(n)) of the complementary equation a(n) = 2·a(n-1) - a(n-2) + b(n-1) + b(n); see Comments. A305330

a(n+1) = a(n-3) + a(n-2) - a(n-1) + a(n) starting with 1, 2, 3, 4. A180046

Nonprime numbers with a sum of nonprime divisors which is a perfect square. A194580

Decimal expansion of 1/sqrt(78). A20835

Number of tilings of a 5 X n rectangle using straight (3 X 1) trominoes and 2 X 2 tiles. A219969

Number of nX3 0..2 arrays with each element equal to either the maximum or the minimum of its horizontal and vertical neighbors. A183548

Number of (n+2)X4 0..1 arrays with every 3X3 subblock having three equal elements in a row horizontally, vertically, diagonally or antidiagonally exactly two different ways, and new values 0..1 introduced in row major order. A204861