What are the Factors of 155?

The following are the different types of factors of 155:

• Factors of 155: 1, 5, 31, 155

• Sum of Factors of 155: 192

• Negative Factors of 155: -1, -5, -31, -155

• Prime Factors of 155: 5, 31

• Prime Factorization of 155: 5^1 × 31^1

There are two ways to find the factors of 155: using factor pairs, and using prime factorization.

Factor pairs of 155 are any two numbers that, when multiplied together, equal 155. The question to ask is “what two numbers multiplied together equal 155?” Every factor can be paired with another factor, and multiplying the two will result in 155.

To find the factor pairs of 155, follow these steps:

Step 1:

Find the smallest prime number that is larger than 1, and is a factor of 155. For reference, the first prime numbers to check are 2, 3, 5, 7, 11, and 13. In this case, the smallest factor that’s a prime number larger than 1 is 5.

Step 2:

Divide 155 by the smallest prime factor, in this case, 5:

155 ÷ 5 = 31

5 and 31 will make a new factor pair.

Step 3:

Repeat Steps 1 and 2, using 31 as the new focus. Find the smallest prime factor that isn’t 1, and divide 31 by that number. In this case, 31 is the new smallest prime factor:

31 ÷ 31 = 1

Remember that this new factor pair is only for the factors of 31, not 155. So, to finish the factor pair for 155, you’d multiply 5 and 31 before pairing with 1:

5 x 31 = 155

Step 4:

Repeat this process until there are no longer any prime factors larger than one to divide by. At the end, you should have the full list of factor pairs.

Here are all the factor pairs for 155:

(1, 155), (5, 31)

So, to list all the factors of 155: 1, 5, 31, 155

The negative factors of 155 would be: -1, -5, -31, -155

To find the Prime factorization of 155, we break down all the factors of 155 until we are left with only prime factors. We then express n as a product of multiplying the prime factors together.

The process of finding the prime factorization of 155 only has a few differences from the above method of finding the factors of 155. Instead of ensuring we find the right factor pairs, we continue to factor each step until we are left with only the list of smallest prime factors greater than 1.

Here are the steps for finding the prime factorization of 155:

Step 1:

Find the smallest prime number that is larger than 1, and is a factor of 155. For reference, the first prime numbers to check are 2, 3, 5, 7, 11, and 13. In this case, the smallest factor that’s a prime number larger than 1 is 5.

Step 2:

Divide 155 by the smallest prime factor, in this case, 5

155 ÷ 5 = 31

5 becomes the first number in our prime factorization.

Step 3:

Repeat Steps 1 and 2, using 31 as the new focus. Find the smallest prime factor that isn’t 1, and divide 31 by that number. The smallest prime factor you pick for 31 will then be the next prime factor. If you keep repeating this process, there will be a point where there will be no more prime factors left, which leaves you with the prime factors for prime factorization.

So, the unique prime factors of 155 are: 5, 31

Practice your factoring skills by exploring how to factor other numbers, like the ones below:

Factors of 14 - The factors of 14 are 1, 2, 7, 14

Factors of 3 - The factors of 3 are 1, 3

Factors of 146 - The factors of 146 are 1, 2, 73, 146

Factors of 135 - The factors of 135 are 1, 3, 5, 9, 15, 27, 45, 135