Each of the elements that are involved in a multiplication.
Example
In the multiplication 24 × 7 = 168, the numbers 24 and 7 are called factors and the number 168 is called the product.
Educational Note
Historical Note
In Latin, factor means “a person who does or makes“. In Greek, in Euclid’s Elements, the word that indicates a factor of a product is “pleura“, which means “side”, because geometrically, the product is considered as the area of a rectangle and the lengths of the sides are the factors of the product.