Properties of the Number 20970

Twenty Thousand Nine Hundred Seventy

Basics

Value: 20969 → 20970 → 20971

Parity: even

Prime: No

Previous Prime: 20963

Next Prime: 20981

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 × 3 ² × 5 × 233

Divisors: 1, 2, 3, 5, 6, 9, 10, 15, 18, 30

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000111101010

Octal: 50752

Duodecimal: 10176

Hexadecimal: 51ea

Square: 439740900

Square Root: 144.81022063376605

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

The number of edges formed when every pair of n points, placed at the vertices of a regular n-gon, are connected by a circle and where the points lie at the ends of the circle's diameter. A358783

Number of polyominoes consisting of 6 regular unit n-gons. A103472

T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with every element equal to or 1 greater than any northeast neighbor modulo n and the upper left element equal to 0. A267836

Number of ways to remove n oranges from an infinite stack of oranges whose m-th layer is an m X m square. A274582

Let G_n denote the planar graph defined in A358746 with the addition, if n is odd, of the circle containing the initial n points; sequence gives the number of edges in G_n. A370977

Sum of the squares of numbers of nonconsecutive tableaux over all partitions of n. A214087

Number of edges in the directed graph for the Reversed Zeckendorf game with starting number n. A389617

Period of continued fraction for square roots of primorials. A64486

Number of nX2 arrays containing 2 copies of 0..n-1 with every element equal to or 1 greater than any northeast neighbor modulo n and the upper left element equal to 0. A267832

G.f. satisfies: A(x) = 1 + x*∑_n>=0 (A(x)² - 1)ⁿ. A192945