Properties of the Number 18321

Eighteen Thousand Three Hundred Twenty-One

Basics

Value: 18320 → 18321 → 18322

Parity: odd

Prime: No

Previous Prime: 18313

Next Prime: 18329

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 31 × 197

Divisors: 1, 3, 31, 93, 197, 591, 6107, 18321

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100011110010001

Octal: 43621

Duodecimal: A729

Hexadecimal: 4791

Square: 335659041

Square Root: 135.35508856337836

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

Fibonacci sequence beginning 4,9. A22130

a(n) = 5·n*a(n-1) + 1 with a(0)=1. A56546

Numbers m with C(2·m, m) + prime(m) prime, where C(2·m, m) = (2·m)!/(m!)². A236242

Number of poly-IH64-tiles (holes allowed) with n cells. A151525

Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of the e.g.f. exp(x)/(1 - k·x). A320031

Main diagonal of the Stolarsky array. A35489

Values of·in the solutions to x² - 3xy + y² + 29 = 0, where 0 < x < y. A218735

Main diagonal of Wythoff array: w(n,n)=[ n*τ ]F(n+1)+(n-1)F(n), where τ=(1+sqrt(5))/2, F(n) = Fibonacci numbers. A20941

Numbers n such that the sum of the prime distinct divisors of n²+1 equals 2 times the difference between the largest and the smallest prime divisor. A200071

a(n) = F(n+1)⁴ - 4·F(n-1)*F(n)³, where F(n) = A000045(n), the n-th Fibonacci number. A318404