refactorable number


A refactorable numberMathworldPlanetmath or tau number is an integer n that is divisible by the count of its divisorsMathworldPlanetmathPlanetmath, or to put it algebraically, n is such that τ(n)|n, with τ(n) being the divisor functionDlmfDlmfMathworldPlanetmath. The first few refactorable numbers are listed in the OEIS A033950 are 1, 2, 8, 9, 12, 18, 24, 36, 40, 56, 60, 72, 80, 84, 88, 96. The equation gcd(n,x)=τ(n) has solutions only if n is a refactorable number.

Title refactorable number
Canonical name RefactorableNumber
Date of creation 2013-03-22 17:40:41
Last modified on 2013-03-22 17:40:41
Owner CompositeFan (12809)
Last modified by CompositeFan (12809)
Numerical id 4
Author CompositeFan (12809)
Entry type Definition
Classification msc 11A25