Factors of 80
Every whole number that divides 80 exactly, the factor pairs, and how to find them yourself.
The answer
The factors of 80 are 1, 2, 4, 5, 8, 10, 16, 20, 40 and 80.
Factor pairs of 80
| Pair | Makes |
|---|---|
| 1 × 80 | 80 |
| 2 × 40 | 80 |
| 4 × 20 | 80 |
| 5 × 16 | 80 |
| 8 × 10 | 80 |
Prime factors of 80
- Prime factorisation
- 80 = 2 × 2 × 2 × 2 × 5 (2⁴ × 5)
- Reading index form
- A small raised number tells you how many times to use that factor. For example, 2³ means 2 × 2 × 2.
- Is 80 prime?
- No. It has 10 factors, not just 1 and 80.
- Is 80 a square number?
- No. 8 × 8 = 64 and 9 × 9 = 81, so 80 falls between two square numbers.
How to find the factors of 80
80 is even, so 2 is sure to be a factor. It ends in 0, so 5 is a factor. Work up from 1 to 8, and write down both numbers in every pair you find.
- 80 ÷ 1 = 80, so 1 × 80 is a pair.
- 80 ÷ 2 = 40, so 2 × 40 is a pair.
- 3 does not go into 80 exactly.
- 80 ÷ 4 = 20, so 4 × 20 is a pair.
- 80 ÷ 5 = 16, so 5 × 16 is a pair.
- 6 does not go into 80 exactly.
- 7 does not go into 80 exactly.
- 80 ÷ 8 = 10, so 8 × 10 is a pair.
Stop at 9: 9 × 9 = 81, which is more than 80. The next pair you would find is 10 × 8, which is 8 × 10 turned round, so you already have every pair.
80 in the times tables
4 × 20 = 80, 5 × 16 = 80 and 8 × 10 = 80. Practise the 8 times table, 10 times table, 16 times table and 20 times table.
More numbers
Check whether 80 is prime.
Questions parents ask
What is the largest factor of 80, apart from 80 itself?
40. Divide 80 by its smallest factor above 1, which is 2: 80 ÷ 2 = 40.
What do the factors of 80 add up to?
186. Leaving out 80 itself, they add up to 106, which is more than 80, so 80 is called an abundant number.
Which number after 80 has the same number of factors?
112. Like 80, it has exactly 10 factors.
Continue your number practice
Explore the diagnostic for another set of practice questions.