Properties of the Number 18209

Eighteen Thousand Two Hundred Nine

Basics

Value: 18208 → 18209 → 18210

Parity: odd

Prime: No

Previous Prime: 18199

Next Prime: 18211

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 131 × 139

Divisors: 1, 131, 139, 18209

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100011100100001

Octal: 43441

Duodecimal: A655

Hexadecimal: 4721

Square: 331567681

Square Root: 134.94072772888103

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

a(n) = prime(n)*prime(n+2). A90076

T(n,k)=Number of (n+2)X(k+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00010101. A260106

Sequence of pairwise relatively prime numbers of class P₅ (see comment in A275246). A275249

Number of labeled T₀-hypergraphs with n distinct hyperedges (empty hyperedge excluded). A59089

Numbers k such that exactly three d in the range d <= k/2 exist which divide binomial(k-d-1,d-1) and which are not coprime to k. A178099

S₅ sequence in partition of integers > 1 described in A240521. A240522

Semiprimes whose prime factors are of equal binary length and which differ from each other in one bit position only. A261073

a(n) = 2·a(n-1) + 5·a(n-2), a(0) = 1, a(1) = 3. A180168

Semiprimes whose prime factors differ from each other in one bit position only. A261077

Expansion of e.g.f.: exp(tan(tanh(x))). A9241