Factors of 155
The factors of 155 are 1, 5, 31, and 155. In total, 155 has 4 factors. Its prime factorization is 5 × 31, and the sum of all its factors is 192.
All factors of 155
Here are all 4 factors of 155, listed from smallest to largest.
Factor pairs of 155
These 2 pairs of whole numbers each multiply to give 155.
Prime factorization of 155
Dividing 155 by the smallest prime at each step gives its prime factorization:
The distinct prime factors of 155 are 5, 31. To factorize any other number, use the prime factorization calculator.
Factor tree of 155
A factor tree shows the same prime factorization visually. Each composite branch splits until every endpoint is a prime number.
Properties of 155
| Number of factors | 4 |
|---|---|
| Sum of factors | 192 |
| Sum of proper factors | 37 |
| Prime factorization | 5 × 31 |
| Prime or composite? | Composite |
| Even or odd? | Odd |
| Perfect square? | No |
| Perfect cube? | No |
| Classification | Deficient |
What makes 155 interesting
- 155 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.
- 155 is a deficient number: its proper factors sum to 37, which is 118 less than 155 itself.
How to find the factors of 155 yourself
Divide 155 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 √155 ≈ 12.45, because every factor above that pairs with one below it.
Reading both columns gives every factor: 1, 5, 31, 155. The factor calculator does this automatically for any number.
Related numbers
Numbers mathematically connected to 155.
Frequently asked questions about 155
What are the factors of 155?
Is 155 a prime number?
What is the prime factorization of 155?
What two numbers multiply to give 155?
What is the sum of the factors of 155?
Is 155 a perfect square?
What is the largest factor of 155 other than itself?
How many factors does 155 have?
Explore more
Try another number in the factor calculator, break 155 down further with the prime factorization calculator, or compare 155 with another number using the GCF calculator and LCM calculator. For divisor counts and sums, see the divisor calculator.