Factors of 51
The factors of 51 are 1, 3, 17, and 51. In total, 51 has 4 factors. Its prime factorization is 3 × 17, and the sum of all its factors is 72.
All factors of 51
Here are all 4 factors of 51, listed from smallest to largest.
Factor pairs of 51
These 2 pairs of whole numbers each multiply to give 51.
Prime factorization of 51
Dividing 51 by the smallest prime at each step gives its prime factorization:
The distinct prime factors of 51 are 3, 17. To factorize any other number, use the prime factorization calculator.
Factor tree of 51
A factor tree shows the same prime factorization visually. Each composite branch splits until every endpoint is a prime number.
Properties of 51
| Number of factors | 4 |
|---|---|
| Sum of factors | 72 |
| Sum of proper factors | 21 |
| Prime factorization | 3 × 17 |
| Prime or composite? | Composite |
| Even or odd? | Odd |
| Perfect square? | No |
| Perfect cube? | No |
| Classification | Deficient |
What makes 51 interesting
- 51 is a composite number, meaning it has more than two factors. It can be written as a product of smaller whole numbers in 2 different ways.
- 51 is a deficient number: its proper factors sum to 21, which is 30 less than 51 itself.
How to find the factors of 51 yourself
Divide 51 by each whole number starting from 1. Whenever the division leaves no remainder, both the divisor and the quotient are factors. You only need to test up to √51 ≈ 7.14, because every factor above that pairs with one below it.
Reading both columns gives every factor: 1, 3, 17, 51. The factor calculator does this automatically for any number.
Related numbers
Numbers mathematically connected to 51.
Frequently asked questions about 51
What are the factors of 51?
Is 51 a prime number?
What is the prime factorization of 51?
What two numbers multiply to give 51?
What is the sum of the factors of 51?
Is 51 a perfect square?
What is the largest factor of 51 other than itself?
How many factors does 51 have?
Explore more
Try another number in the factor calculator, break 51 down further with the prime factorization calculator, or compare 51 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.