The factors of 78 are 1, 2, 3, 6, 13, 26, 39 and 78. The factors of a number are found by breaking the number down into all the combinations of positive integers that can be combined through multiplication to form the number. This is called factorization.
Positive integers are the numbers used when counting. Every positive integer has 1 and itself as factors. This is because 1 times any number gives that number as a result. More factors are found by dividing the number by 2 and then 3, working through the integers in succession. Whenever the answer to the division problem is a positive integer, the two numbers are factors of the original number. For example, when 78 is divided by 6 the answer is 13, so 6 and 13 are factors of 78. On the other hand, 78 divided by 8 equals 9.75. That is not a positive integer, so 8 is not a factor of 78. When working with large numbers, a calculator makes the process go quicker.
The prime factorization of a number is a list of all of its prime factors in multiplication form. Prime numbers have no other factors besides 1 and themselves. The prime factorization of 78 is 2 x 3 x 13. Every positive integer that is not a prime number has one unique prime factorization.