Properties of the Number 18806

Eighteen Thousand Eight Hundred Six

Basics

Value: 18805 → 18806 → 18807

Parity: even

Prime: No

Previous Prime: 18803

Next Prime: 18839

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 × 9403

Divisors: 1, 2, 9403, 18806

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100100101110110

Octal: 44566

Duodecimal: AA72

Hexadecimal: 4976

Square: 353665636

Square Root: 137.13497001129946

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

Numbers k such that 2·3^k - 1 is prime. A3307

Triangular array formed from successive differences of factorial numbers. A47920

a(n) = n·a(n-1) + (n-2)*a(n-2), a(0) = 0, a(1) = 2. A55790

Euler's difference table: triangle read by rows, formed by starting with factorial numbers (A000142) and repeatedly taking differences. T(n,n) = n!, T(n,k) = T(n,k+1) - T(n-1,k). A68106

6th differences of factorial numbers. A23043

G.f. satisfies: A(x) = (1 + x·A(x)³) * (1 + x²*A(x)²). A200717

Triangle T[n,m]: T[n,-1] = 0; T[0,0] = 0; T[n,0] = n·n!; T[n,m] = T[n,m-1] - T[n-1,m-1]. A61312

Difference triangle of factorial numbers read by upward diagonals. A116853

Indices of the start of 10 successive distinct digits in the decimal expansion of π. A258157

Twice the area of the convex hull around dragon curve expansion level n. A341029