Factors of 78
Every whole number that divides 78 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 78 are 1, 2, 3, 6, 13, 26, 39 and 78.
Factor pairs of 78
| Pair | Makes |
|---|---|
| 1 × 78 | 78 |
| 2 × 39 | 78 |
| 3 × 26 | 78 |
| 6 × 13 | 78 |
Prime factors of 78
- Prime factorisation
- 78 = 2 × 3 × 13
- Is 78 prime?
- No. It has 8 factors, not just 1 and 78.
- Is 78 a square number?
- No. 8 × 8 = 64 and 9 × 9 = 81, so 78 falls between two square numbers.
How to find the factors of 78
78 is even, so 2 is sure to be a factor. Its digits add up to 15, a multiple of 3, so 3 is a factor. Work up from 1 to 8, and write down both numbers in every pair you find.
- 78 ÷ 1 = 78, so 1 × 78 is a pair.
- 78 ÷ 2 = 39, so 2 × 39 is a pair.
- 78 ÷ 3 = 26, so 3 × 26 is a pair.
- 4 does not go into 78 exactly.
- 5 does not go into 78 exactly.
- 78 ÷ 6 = 13, so 6 × 13 is a pair.
- 7 does not go into 78 exactly.
- 8 does not go into 78 exactly.
Stop at 9: 9 × 9 = 81, which is more than 78. The next pair you would find is 13 × 6, which is 6 × 13 turned round, so you already have every pair.
78 in the times tables
6 × 13 = 78. Practise the 13 times table.
More numbers
Check whether 78 is prime.
Questions parents ask
What is the largest factor of 78, apart from 78 itself?
39. Divide 78 by its smallest factor above 1, which is 2: 78 ÷ 2 = 39.
What do the factors of 78 add up to?
168. Leaving out 78 itself, they add up to 90, which is more than 78, so 78 is called an abundant number.
Which number after 78 has the same number of factors?
88. Like 78, it has exactly 8 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.