Properties of the Number 18669

Eighteen Thousand Six Hundred Sixty-Nine

Basics

Value: 18668 → 18669 → 18670

Parity: odd

Prime: No

Previous Prime: 18661

Next Prime: 18671

Digit Sum: 30

Digital Root: 3

Palindrome: No

Factorization: 3 × 7 ² × 127

Divisors: 1, 3, 7, 21, 49, 127, 147, 381, 889, 2667

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100100011101101

Octal: 44355

Duodecimal: A979

Hexadecimal: 48ed

Square: 348531561

Square Root: 136.63454907160195

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·k is a partition number. A213179

a(n) = 1 + (1200 + (634 + (225 + (85 + (15 + n)*n)*n)*n)*n)*n/720. A145128

a(n) = ∑_{k=0..floor(2·n/7)} binomial(3·k,2·n-7·k). A392436

Number of (w,x,y,z) with all terms in {1,...,n} and w<2x and y<=3z. A212509

Column 4 of table A390148. A390465

Number of rules of a context-free grammar in Chomsky normal form that generates all permutations of n symbols. A90326

Number of connected graphs, where vertices are labeled with positive integers summing to n, and where identically labeled vertices are indistinguishable and cannot be connected with an edge. A337717

Integers k such that φ(prime(k)+1) = φ(prime(k)-1). A66902

Matrix product of Stirling1-triangle A008275(n,k) and unsigned Lah-triangle |A008297(n,k)|. A79639

a(n) = A154798(n)/2. A163288