Properties of the Number 20409

Twenty Thousand Four Hundred Nine

Basics

Value: 20408 → 20409 → 20410

Parity: odd

Prime: No

Previous Prime: 20407

Next Prime: 20411

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 6803

Divisors: 1, 3, 6803, 20409

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100111110111001

Octal: 47671

Duodecimal: B989

Hexadecimal: 4fb9

Square: 416527281

Square Root: 142.8600713985542

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

T(n,k)=Number of n-bead necklaces labeled with numbers -k..k not allowing reversal, with sum zero and three times sum of squares <= n·k*(k+1). A208814

Number of dominating sets in the n-triangular grid graph. A287064

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 100 ones. A31868

Expansion of ∏_k>=1 1/(1 - x^k)^mod(k,3). A301589

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 590", based on the 5-celled von Neumann neighborhood. A273117

Number of nX3 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. A300345

Number of n-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero and three times sum of squares <= n²*(n+1). A208806

Number of n-bead necklaces labeled with numbers -6..6 not allowing reversal, with sum zero and three times sum of squares <= n*(6)*(6+1). A208812

T(n,k)=Number of nXk 0..1 arrays with every element equal to 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. A300350

Simple continued fraction expansion of an infinite product. A221073