unitary divisor

Given the divisors $d_i$ of an integer $n$, if it is the case that for a particular $d_i$ the equality $\gcd (d_i,\frac{n}{d_i})=1$ holds true, then $d_i$ is called a unitary divisor of $n$. For example, the unitary divisors of 120 are 1, 3, 5, 8, 15, 24, 40, 120 (while 2, 4, 6, 10, 12, 20, 30, 60 are proper divisors but not unitary divisors). All the divisors of squarefree numbers are also unitary divisors.

Title	unitary divisor
Canonical name	UnitaryDivisor
Date of creation	2013-03-22 16:53:20
Last modified on	2013-03-22 16:53:20
Owner	CompositeFan (12809)
Last modified by	CompositeFan (12809)
Numerical id	4
Author	CompositeFan (12809)
Entry type	Definition
Classification	msc 11A51