What is the term for a number that divides exactly into two or more other numbers?

The term for a number that divides exactly into two or more other numbers is a common factor. Common factors are the numbers that can evenly divide two or more integers without leaving any remainder. For example, if you consider the numbers 12 and 18, the common factors are 1, 2, 3, and 6 because all these numbers can divide both 12 and 18 without leaving a remainder.

The greatest common factor, on the other hand, is specifically the highest number that divides two or more numbers. While it relates to common factors, it specifically identifies the largest one, so it wouldn't apply universally.

Least common multiple refers to the smallest number that is a multiple of two or more numbers, which is quite different from what is being defined here.

Prime factors are the prime numbers that can multiply together to form a given number. They do not represent the concept of divisibility among two or more numbers in the same way that common factors do.

Thus, common factor is the most accurate term for a number dividing exactly into multiple other numbers.