Properties of the Number 42081

Forty-Two Thousand Eighty-One

Basics

Value: 42080 → 42081 → 42082

Parity: odd

Prime: No

Previous Prime: 42073

Next Prime: 42083

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 13 ² × 83

Divisors: 1, 3, 13, 39, 83, 169, 249, 507, 1079, 3237

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1010010001100001

Octal: 122141

Duodecimal: 20429

Hexadecimal: a461

Square: 1770810561

Square Root: 205.1365398947735

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) = -a(n-1) - a(n-2) + a(n-3), a(0)=3, a(1)=-1, a(2)=-1. A73145

a(n) = number of Egyptian fractions 1 = 1/x₁ + ... + 1/x_k (for any k), 0<x₁<...<x_k=n. A92669

a(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 1, a(1) = a(2) = 7. A214829

Inverted (definition in A075193) generalized tribonacci numbers A001644. A75298

Nonzero elements of A092669. A92672

Numbers k such that 10^k + 81 is prime. A137848

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 417", based on the 5-celled von Neumann neighborhood. A272018

Expansion of ∏_k>=1 (1 + x^2·k-1)^k*(k-1/2). A294777

Number of 5-tuples of different integers from [ 2,n ] with no common factors among quadruples. A15645

Denominators of continued fraction convergents to sqrt(564). A42081