Properties of the Number -20728

Twenty Thousand Seven Hundred Twenty-Eight

Basics

Value: -20729 → -20728 → -20727

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ³ × 2591

Divisors: 1, 2, 4, 8, 2591, 5182, 10364, 20728

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -101000011111000

Octal: -50370

Duodecimal: -BBB4

Hexadecimal: -50f8

Square: 429649984

Square Root: 143.97221954252146

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) is the number of regions formed by n-secting the angles of an octagon. A335769

E.g.f. satisfies A(x) = exp(x * (1 + x + x² + x³) * A(x⁴/24)). A367756

a(n) = 64·n² - 8. A158487

Number of permutations of 1..n with displacements restricted to {-6,-5,-4,-3,-1,0,2}. A189594

Number of tilings of a 7 X n rectangle using integer-sided square tiles of area > 1. A226371

Number of length 3 1..(n+2) arrays with no leading or trailing partial sum equal to a prime. A254206

Expansion of 1 / ((1-x)² - x⁴)². A392552

Numbers k such that φ((prime(k)-1)/2) = σ(k). A68474

Expansion of 1/(1 - x⁴ - x⁵ - x⁶ + x¹⁰). A147652

Poincaré series [or Poincare series] P(C#_{3,2}; x). A124630