Properties of the Number 20691

Twenty Thousand Six Hundred Ninety-One

Basics

Value: 20690 → 20691 → 20692

Parity: odd

Prime: No

Previous Prime: 20681

Next Prime: 20693

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 11 ² × 19

Divisors: 1, 3, 9, 11, 19, 33, 57, 99, 121, 171

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000011010011

Octal: 50323

Duodecimal: BB83

Hexadecimal: 50d3

Square: 428117481

Square Root: 143.84366513684222

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

a(n) = n³ + (n+1)³ + (n+2)³. A27602

Numbers that are the sum of 3 positive cubes in 3 or more ways. A25398

T(n,k) = number of defective 3-colorings of an n X k 0..2 array connected horizontally and antidiagonally with exactly two mistakes, and colors introduced in row-major 0..2 order. A229694

Numbers that are the sum of 3 positive cubes in exactly 3 ways. A25397

Trajectory of 9 under map x->x + (x-with-digits-reversed). A33651

Triangle version of the array w(N,L) of the average number of round trips of length L on Laguerre graphs L_N. A201198

Number of parts in all partitions of all the numbers in {1,2,...,n} into distinct parts. A15724

Numbers that are the sum of 3 distinct positive cubes in 3 or more ways. A25402

a(n) = n*(n-1)*(n² + 2)/6. A71244

a(n) = prime(n) * prime(n+2) - 2·prime(n+1). A152532