Properties of the Number 20928

Twenty Thousand Nine Hundred Twenty-Eight

Basics

Value: 20927 → 20928 → 20929

Parity: even

Prime: No

Previous Prime: 20921

Next Prime: 20929

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 2 ⁶ × 3 × 109

Divisors: 1, 2, 3, 4, 6, 8, 12, 16, 24, 32

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101000111000000

Octal: 50700

Duodecimal: 10140

Hexadecimal: 51c0

Square: 437981184

Square Root: 144.665130560201

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 nXk 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors. A209100

T(n,k) = Number of (n+2) X (k+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 1 and no antidiagonal sum 1 and no row sum 1 and no column sum 1. A255101

Number of 4-way intersections in the interior of a regular 6n-gon. A137938

∑_i=0..n ∑_j=0..n (i AND j), where AND is the binary logical AND operator. A224924

Truncated tetrahedral numbers: a(n) = (1/6)*(n+1)*(23·n² + 19·n + 6). A5906

Expansion of (1/4)(1-sqrt(1-12x)/sqrt(1-4x)). A138240

Expansion of e.g.f. 1/(1 + x·log(1-2·x)). A367883

Number of n X 4 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors. A209096

Number of 3 X n 0..2 arrays with new values 0..2 introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors. A209102

Number of (n+2)X(3+2) 0..1 arrays with no 3x3 subblock diagonal sum 1 and no antidiagonal sum 1 and no row sum 1 and no column sum 1. A255096