Factors of 4
Every whole number that divides 4 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 4 are 1, 2 and 4.
Factor pairs of 4
| Pair | Makes |
|---|---|
| 1 × 4 | 4 |
| 2 × 2 | 4 |
2 × 2 uses the same number twice, so 2 counts once. That is why 4 has an odd number of factors: 3.
Prime factors of 4
- Prime factorisation
- 4 = 2 × 2 (2²)
- Is 4 prime?
- No. It has 3 factors, not just 1 and 4.
- Is 4 a square number?
- Yes. 2 × 2 = 4.
How to find the factors of 4
4 is even, so 2 is sure to be a factor. It is a square number, so one pair is 2 × 2, the same number twice. Work up from 1 to 2, and write down both numbers in every pair you find.
- 4 ÷ 1 = 4, so 1 × 4 is a pair.
- 4 ÷ 2 = 2, so 2 × 2 is a pair.
Stop at 3: 3 × 3 = 9, which is more than 4. The next pair you would find is 4 × 1, which is 1 × 4 turned round, so you already have every pair.
4 in the times tables
2 × 2 = 4. Practise the 2 times table.
More numbers
Check whether 4 is prime or see the square root of 4.
Questions parents ask
What is the largest factor of 4, apart from 4 itself?
2. Divide 4 by its smallest factor above 1, which is 2: 4 ÷ 2 = 2.
What do the factors of 4 add up to?
7. Leaving out 4 itself, they add up to 3, which is less than 4, so 4 is called a deficient number.
Which number after 4 has the same number of factors?
9. Like 4, it has exactly 3 factors.
Number facts are the base of 11+ maths
Factors, multiples, primes and square numbers come up all over 11+ maths, from simplifying fractions to ratio. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.