Properties of the Number 42808

Forty-Two Thousand Eight Hundred Eight

Basics

Value: 42807 → 42808 → 42809

Parity: even

Prime: No

Previous Prime: 42797

Next Prime: 42821

Digit Sum: 22

Digital Root: 4

Palindrome: No

Factorization: 2 ³ × 5351

Divisors: 1, 2, 4, 8, 5351, 10702, 21404, 42808

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1010011100111000

Octal: 123470

Duodecimal: 20934

Hexadecimal: a738

Square: 1832524864

Square Root: 206.9009424821453

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

Expansion of 1/(1+4·x*c(x)), c(x) the g.f. of Catalan numbers A000108. A126986

Triangle read by rows: T(n,k) = number of permutations p of 1,...,n, with min(|p(i)-p(i-1)|, i=2..n) = k (n>=2, k>=1). A129534

Let u(1)=u(2)=1, u(3)=2n, u(k) = abs(u(k-1)-u(k-2)-u(k-3)) and M(k) = Max_i<=i<=k u(i), then for any k >= A078109(n), M(k) = floor(sqrt(k + a(n))). A78108

a(n) = floor( n*(n-1)*(n-2)*(n-3)/26 ). A11936

Sum of the lengths of the first descents in all bargraphs having semiperimeter n (n>=2). A descent is a maximal sequence of consecutive down steps. A276068

The number of integer partitions P of n such that either the length k of P is not a part or P has at least one part equal to 1 (or both). A229863

Numbers k such that (11·10^k - 113) / 3 is prime. A280557

Numerators of continued fraction convergents to sqrt(935). A42808