A factor or a divisor is a number that will divide into another number evenly and leaving no remainder.
common factor
This would be called a "factor". A number may be made by multiplying two or more other numbers together. The numbers that are multiplied together are called factors of the final number.
common factor
That would be called a "common factor" of the two (or more) numbers.
Like 21? Prime numbers.
A factor.
A factor.
factor
common factor
Each number is called a factor. The answer is the product.
That's called the greatest common factor, or GCF.
prime number