Properties of the Number 19839

Nineteen Thousand Eight Hundred Thirty-Nine

Basics

Value: 19838 → 19839 → 19840

Parity: odd

Prime: No

Previous Prime: 19819

Next Prime: 19841

Digit Sum: 30

Digital Root: 3

Palindrome: No

Factorization: 3 × 17 × 389

Divisors: 1, 3, 17, 51, 389, 1167, 6613, 19839

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 100110101111111

Octal: 46577

Duodecimal: B593

Hexadecimal: 4d7f

Square: 393585921

Square Root: 140.85098508707705

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

Number of bracelet structures using a maximum of five different colored beads. A56355

Array read by antidiagonals: T(n,k) is the number of color patterns (set partitions) in an unoriented cycle of length n using k or fewer colors (subsets). A320748

a(n) = ∑_i=1..n (prime(i)ⁿ - 1)/(prime(i) - 1). A124271

Transform of the finite sequence (1, 0, -1, 0, 1) by the T_1,1 transformation (see link). A159330

an=n-th smallest integer m=p1·p2·p3, product of 3 odd primes such that d+2m/d are all primes for d dividing 2m. A128278

Numbers m such that m·reversal(m) contains every decimal digit exactly once. A178929

Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 19 ones. A31787

G.f. is the continued fraction: A(x) = 1/[1 - x/[1 - (x-x²)/[1 - (x²-x⁴)/[1 - (x³-x⁶)/[1-... - (xⁿ-x²ⁿ)/[1 - ... ]]]]]]]. A99823

a(n) = floor(sqrt(π(2ⁿ))). A133498

First nonzero digit in the decimal expansion of 1/n. A52038