Factors of 4

The factors of 4 are 1, 2, and 4. In total, 4 has 3 factors. Its prime factorization is 2², and the sum of all its factors is 7. 4 is also a perfect square, equal to 2 × 2.

All factors of 4

Here are all 3 factors of 4, listed from smallest to largest.

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Factor pairs of 4

These 2 pairs of whole numbers each multiply to give 4.

1 × 4 = 4

2 × 2 = 4

Notice the pair (2, 2) — because 4 is a perfect square, this pair uses the same number twice.

Prime factorization of 4

Dividing 4 by the smallest prime at each step gives its prime factorization:

4 ÷ 2 = 2

2 ÷ 2 = 1

Result: 4 = 2 × 2 = 2²

The distinct prime factors of 4 are 2. To factorize any other number, use the prime factorization calculator.

Factor tree of 4

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

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

Properties of 4

Number of factors	3
Sum of factors	7
Sum of proper factors	3
Prime factorization	2²
Prime or composite?	Composite
Even or odd?	Even
Perfect square?	Yes (2²)
Perfect cube?	No
Classification	Deficient

What makes 4 interesting

4 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 2 different ways.
4 is a perfect square: 2 × 2 = 4. This is why it has an odd number of factors (3) — the pair (2, 2) counts only once.
4 is a deficient number: its proper factors sum to 3, which is 1 less than 4 itself.
4 is a highly composite number — it has more factors (3) than any smaller positive integer. Numbers like this are useful in measurement systems because they divide evenly so many ways.
4 is a prime power: it is 2 raised to the power of 2. All of its factors are powers of 2.

How to find the factors of 4 yourself

Divide 4 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 √4 ≈ 2.00, because every factor above that pairs with one below it.

4 ÷ 1 = 4 ✓

4 ÷ 2 = 2 ✓

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

Numbers mathematically connected to 4.

Frequently asked questions about 4

What are the factors of 4?

The factors of 4 are 1, 2, and 4. That is 3 factors in total, counting both 1 and 4.

Is 4 a prime number?

No, 4 is not prime — it is a composite number with 3 factors. A prime number has exactly two factors, but 4 is also divisible by 2.

What is the prime factorization of 4?

The prime factorization of 4 is 2². Written out in full: 2 × 2 = 4. Its distinct prime factors are 2.

What two numbers multiply to give 4?

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

What is the sum of the factors of 4?

Adding all the factors of 4 together gives 7. Excluding 4 itself, the proper factors sum to 3.

Is 4 a perfect square?

Yes, 4 is a perfect square. It equals 2 × 2. Perfect squares always have an odd number of factors — 4 has 3.

What is the largest factor of 4 other than itself?

The largest factor of 4 apart from 4 itself is 2, since 4 ÷ 2 = 2.

How many factors does 4 have?

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

Explore more

Try another number in the factor calculator, break 4 down further with the prime factorization calculator, or compare 4 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.