Properties of the Number 28006

Twenty-Eight Thousand Six

Basics

Value: 28005 → 28006 → 28007

Parity: even

Prime: No

Previous Prime: 28001

Next Prime: 28019

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 2 × 11 × 19 × 67

Divisors: 1, 2, 11, 19, 22, 38, 67, 134, 209, 418

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 110110101100110

Octal: 66546

Duodecimal: 1425A

Hexadecimal: 6d66

Square: 784336036

Square Root: 167.34993277560645

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

Number T(n,k) of entries in the k-th cycles of all permutations of [n] when cycles are ordered by increasing lengths (and increasing smallest elements); triangle T(n,k), n>=1, 1<=k<=n, read by rows. A322383

The number of edges in a graph induced by a regular drawing of K_n,n. A290132

G.f.: (1 + 5·x + 5·x² + x³)/∏_i=1..10 (1 - xⁱ). A256977

Number of ways to place 3 nonattacking bishops on a 3 X n board. A172207

G.f. satisfies: A(x) = ∑_n>=0 (A(x)ⁿ - 1)ⁿ * xⁿ / (1-2·x)ⁿ⁺¹. A251181

An oscillating sequence: a(n) = n² + 2^n-1 - 2·a(n-1), n>0, with a(1) = 1. A238315

Number of entries in the seventh cycles of all permutations of [n] when cycles are ordered by increasing lengths. A332911

Expansion of 1/((1-2x)(1-7x)(1-8x)(1-10x)). A28006