Multiple
A multiple of a given integer is the product of that integer with some other integer. Thus 
is a multiple of 
exactly when can be written in the form 
where 
and are integers. (In this case, is a multiple of , as well).
Every nonzero integer has an infinite number of multiples. As an example, a few of the multiples of 15 are 15, 30, 45, 60, and 75. A few of the multiples of 3 are 3, 6, 9, 12, and 15.
An equivalent phrasing is that is a multiple of exactly when is divisble by .
