Proper factors are all factors except for the number itself in this case 18

1, 2, 3, 6, 9

Prime factorization for 18

18 = 2 x 9 <--- 2 is a prime number

Reduce 9 to the product of primes:

9 = 3 x 3 <--- 3 is a prime number

Reduce 3 to the product of primes:

Show prime factorization:

2 x 3 x 3

Prime Power Decomposition

2 x 3^{2}

Show the sum of factors (divisors) for 18

1 + 18 + 2 + 9 + 3 + 6 = 39

Show the aliquot sum:

This is the sum of all the factors except the number

1 + 2 + 9 + 3 + 6 = 21

Common Core State Standards In This Lesson

4.OA.A.4

What is the Answer?

1, 2, 3, 6, 9, 18

How does the Factorization Calculator work?

Free Factorization Calculator - Given a positive integer, this calculates the following for that number:
1) Factor pairs and prime factorization and prime power decomposition
2) Factors and Proper Factors
3) Aliquot Sum This calculator has 1 input.

What 3 formulas are used for the Factorization Calculator?

Find all pairs that have a product equal to the number you want to factor For factors in step 1, find the prime factorization for each number