Enter a whole number to list all its factors and factor pairs, and see its prime factorization.
A factor of a whole number is any whole number that divides it with nothing left over. The factors of 12 are 1, 2, 3, 4, 6 and 12. Factors come in pairs that multiply to give the number: 1 × 12, 2 × 6 and 3 × 4. If a number is a perfect square, one pair repeats the same number twice, as in 6 × 6 for 36. Every whole number above 1 has at least two factors, 1 and itself.
A prime number has exactly two factors, 1 and itself. The first primes are 2, 3, 5, 7, 11 and 13. Every other whole number above 1 can be written as a product of primes in just one way, which is called its prime factorization. For example, 120 is 2 × 2 × 2 × 3 × 5. The calculator finds this by dividing out the smallest prime again and again, and shows the splitting steps like a factor tree.
Factors help you reduce fractions, find common denominators, share items into equal groups and solve algebra problems that involve factoring. The list of factors also gives the greatest common factor and least common multiple of two numbers, which are the next tools for working with fractions and ratios.
Test each whole number from 1 up to the square root of the number. Whenever one divides evenly, it and the result of the division are both factors.
It is the number written as a product of primes. The prime factorization of 36 is 2 × 2 × 3 × 3.
A prime has no factors other than 1 and itself. If the calculator lists only the pair 1 and the number, it is prime.
They are two factors that multiply to give the number. The factor pairs of 12 are (1, 12), (2, 6) and (3, 4).
No. A prime needs exactly two factors, and 1 has only one factor.
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