Factors of 63
Every whole number that divides 63 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 63 are 1, 3, 7, 9, 21 and 63.
Factor pairs of 63
| Pair | Makes |
|---|---|
| 1 × 63 | 63 |
| 3 × 21 | 63 |
| 7 × 9 | 63 |
Prime factors of 63
- Prime factorisation
- 63 = 3 × 3 × 7 (3² × 7)
- Reading index form
- A small raised number tells you how many times to use that factor. For example, 2³ means 2 × 2 × 2.
- Is 63 prime?
- No. It has 6 factors, not just 1 and 63.
- Is 63 a square number?
- No. 7 × 7 = 49 and 8 × 8 = 64, so 63 falls between two square numbers.
How to find the factors of 63
63 is odd, so every even number you try will fail. Its digits add up to 9, a multiple of 9, so 3 and 9 are factors. Work up from 1 to 7, and write down both numbers in every pair you find.
- 63 ÷ 1 = 63, so 1 × 63 is a pair.
- 2 does not go into 63 exactly.
- 63 ÷ 3 = 21, so 3 × 21 is a pair.
- 4 does not go into 63 exactly.
- 5 does not go into 63 exactly.
- 6 does not go into 63 exactly.
- 63 ÷ 7 = 9, so 7 × 9 is a pair.
Stop at 8: 8 × 8 = 64, which is more than 63. The next pair you would find is 9 × 7, which is 7 × 9 turned round, so you already have every pair.
63 in the times tables
7 × 9 = 63. Practise the 7 times table and 9 times table.
More numbers
Check whether 63 is prime.
Questions parents ask
What is the largest factor of 63, apart from 63 itself?
21. Divide 63 by its smallest factor above 1, which is 3: 63 ÷ 3 = 21.
What do the factors of 63 add up to?
104. Leaving out 63 itself, they add up to 41, which is less than 63, so 63 is called a deficient number.
Which number after 63 has the same number of factors?
68. Like 63, it has exactly 6 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.