Unitary Divisor

A Divisor $d$ of $c$ for which

$$\mathop{\rm GCD}\nolimits (d,c/d) = 1,$$

where GCD is the Greatest Common Divisor.

See also Divisor, Greatest Common Divisor, Unitary Perfect Number

References

Guy, R. K. ``Unitary Perfect Numbers.'' §B3 in Unsolved Problems in Number Theory, 2nd ed. New York: Springer-Verlag, pp. 53-59, 1994.