Properties of the Number 19989

Nineteen Thousand Nine Hundred Eighty-Nine

Basics

Value: 19988 → 19989 → 19990

Parity: odd

Prime: No

Previous Prime: 19979

Next Prime: 19991

Digit Sum: 36

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 2221

Divisors: 1, 3, 9, 2221, 6663, 19989

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111000010101

Octal: 47025

Duodecimal: B699

Hexadecimal: 4e15

Square: 399560121

Square Root: 141.38246001537814

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

Coordination sequence for (3,3,6) tiling of hyperbolic plane. A265073

Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=2, I={0,1}. A80013

Sum of numbers of y-multisets of divisors of·for each x >= 1, y >= 0, x + y = n. A343661

Triangle T, read by rows, such that the matrix cube shifts T one place diagonally left and upward, with T(n, 0) = T(n, n) = 1 for n>=0. A96744

a(n) = Lucas(n) concatenated with Fibonacci(n). A247337

Number of (1+1) X (n+1) arrays of permutations of 0..n·2+1 with each element having directed index change -1,1 0,-1 0,1 or 1,0. A264507

a(n) = (F(2n+1) + F(2n-1) + F(n+3) - 2)/2, where F() = Fibonacci numbers A000045. A5593

Expansion of (1-x)^-1/(1+2·x+2·x²-2·x³). A77932

Expansion of e.g.f. (3 - 2·exp(x))^3/2. A375991

Indices n such that A307672(2·n) = 0. A19989