Properties of the Number 19809

Nineteen Thousand Eight Hundred Nine

Basics

Value: 19808 → 19809 → 19810

Parity: odd

Prime: No

Previous Prime: 19801

Next Prime: 19813

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 31 × 71

Divisors: 1, 3, 9, 31, 71, 93, 213, 279, 639, 2201

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 100110101100001

Octal: 46541

Duodecimal: B569

Hexadecimal: 4d61

Square: 392396481

Square Root: 140.7444492688788

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

G.f.: A(x) = ∏_n>=0 (1+a(n)*xⁿ⁺¹)² = ∑_n>=0 a(n)*xⁿ. A93635

a(n) = A003696(n+1)/A001353(n+1). A161158

Decimal expansion of sqrt(2·e)/23. A19809