Factor Calculator

Factors of 428

The factors of 428 are 1, 2, 4, 107, 214, and 428. In total, 428 has 6 factors. Its prime factorization is 2² × 107, and the sum of all its factors is 756.

All factors of 428

Here are all 6 factors of 428, listed from smallest to largest.

124107214428

Factor pairs of 428

These 3 pairs of whole numbers each multiply to give 428.

1 × 428 = 428
2 × 214 = 428
4 × 107 = 428

Prime factorization of 428

Dividing 428 by the smallest prime at each step gives its prime factorization:

428 ÷ 2 = 214
214 ÷ 2 = 107
107 ÷ 107 = 1
Result: 428 = 2 × 2 × 107 = 2² × 107

The distinct prime factors of 428 are 2, 107. To factorize any other number, use the prime factorization calculator.

Factor tree of 428

A factor tree shows the same prime factorization visually. Each composite branch splits until every endpoint is a prime number.

Factor tree of 42842822142107
Prime factors are shown in solid indigo. Composite numbers split into their smallest prime and the quotient.

Properties of 428

Number of factors6
Sum of factors756
Sum of proper factors328
Prime factorization2² × 107
Prime or composite?Composite
Even or odd?Even
Perfect square?No
Perfect cube?No
ClassificationDeficient

What makes 428 interesting

  • 428 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 3 different ways.
  • 428 is a deficient number: its proper factors sum to 328, which is 100 less than 428 itself.

How to find the factors of 428 yourself

Divide 428 by each whole number starting from 1. Whenever the division leaves no remainder, both the divisor and the quotient are factors. You only need to test up to √42820.69, because every factor above that pairs with one below it.

428 ÷ 1 = 428
428 ÷ 2 = 214
428 ÷ 4 = 107

Reading both columns gives every factor: 1, 2, 4, 107, 214, 428. The factor calculator does this automatically for any number.

Frequently asked questions about 428

What are the factors of 428?

The factors of 428 are 1, 2, 4, 107, 214, and 428. That is 6 factors in total, counting both 1 and 428.

Is 428 a prime number?

No, 428 is not prime — it is a composite number with 6 factors. A prime number has exactly two factors, but 428 is also divisible by 2.

What is the prime factorization of 428?

The prime factorization of 428 is 2² × 107. Written out in full: 2 × 2 × 107 = 428. Its distinct prime factors are 2, 107.

What two numbers multiply to give 428?

There are 3 pairs of whole numbers that multiply to 428: 1 × 428, 2 × 214, 4 × 107.

What is the sum of the factors of 428?

Adding all the factors of 428 together gives 756. Excluding 428 itself, the proper factors sum to 328.

Is 428 a perfect square?

No, 428 is not a perfect square. There is no whole number that multiplies by itself to give 428. The nearest perfect squares are 400 and 441.

What is the largest factor of 428 other than itself?

The largest factor of 428 apart from 428 itself is 214, since 428 ÷ 214 = 2.

How many factors does 428 have?

428 has 6 factors: 1, 2, 4, 107, 214, and 428. You can verify this from the prime factorization 2² × 107: add 1 to each exponent and multiply, giving 3 × 2 = 6.

Explore more

Try another number in the factor calculator, break 428 down further with the prime factorization calculator, or compare 428 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.