Factors of 81
81 has 5 factors.
All factors of 81
1, 3, 9, 27, 81
Prime factorization: 3⁴
Number of factors
5
Sum of factors
121
Prime?
No
Factor pairs of 81
Each pair multiplies together to make 81:
| Pair | Product |
|---|---|
| 1 × 81 | 81 |
| 3 × 27 | 81 |
| 9 × 9 | 81 |
Factors of nearby numbers
Factor any number
Need a different number? The prime factorization calculator breaks any number into its prime factors and lists all its divisors.
Frequently asked questions
What are the factors of 81?+
The factors of 81 are 1, 3, 9, 27, 81 — that is 5 factors in total.
What is the prime factorization of 81?+
The prime factorization of 81 is 3⁴.
Is 81 a prime number?+
No. 81 has 5 factors, more than just 1 and itself, so it is a composite number.