Properties of the Number 20998

Twenty Thousand Nine Hundred Ninety-Eight

Basics

Value: 20997 → 20998 → 20999

Parity: even

Prime: No

Previous Prime: 20983

Next Prime: 21001

Digit Sum: 28

Digital Root: 1

Palindrome: No

Factorization: 2 × 10499

Divisors: 1, 2, 10499, 20998

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001000000110

Octal: 51006

Duodecimal: 1019A

Hexadecimal: 5206

Square: 440916004

Square Root: 144.90686664199183

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

T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7. A252407

Number of partitions of n into sums of products. A66815

Number of quadrilateral regions into which a figure made up of a row of n adjacent congruent rectangles is divided upon drawing diagonals of all possible rectangles. A324043

Numerators of continued fraction convergents to sqrt(206). A41382

a(n) = ∑_d∣n A007955(d) * A000027(d) = ∑_d∣n A007955(d) * (d), where A007955(m) = product of divisors of m. A174933

Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7. A252402

Number of (6+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 2 3 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 2 3 4 6 or 7. A252413

The number of lit cells in weakly decreasing partitions of n when light shines from the north west and only the first column is lit. Here partitions are represented from left to right by columns of cells. A366175

Irregular triangle read by rows: T(n,k) is the number of n X n tic-tac-toe positions (up to rotation and reflection) with k tokens (i.e., after k plays) which end a game (n > 0, 0 <= k <= n²). A317576

Numbers with arithmetic derivative which is a palindromic prime number (A002385). A359332