What is the Greatest Common Factor of 155 and 170?

Greatest common factor (GCF) of 155 and 170 is 5.

GCF(155,170) = 5

We will now calculate the prime factors of 155 and 170, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 155 and 170.

How to find the GCF of 155 and 170?

We will first find the prime factorization of 155 and 170. After we will calculate the factors of 155 and 170 and find the biggest common factor number .

Step-1: Prime Factorization of 155

Prime factors of 155 are 5, 31. Prime factorization of 155 in exponential form is:

155 = 5¹ × 31¹

Step-2: Prime Factorization of 170

Prime factors of 170 are 2, 5, 17. Prime factorization of 170 in exponential form is:

170 = 2¹ × 5¹ × 17¹

Step-3: Factors of 155

List of positive integer factors of 155 that divides 155 without a remainder.

1, 5, 31

Step-4: Factors of 170

List of positive integer factors of 170 that divides 155 without a remainder.

1, 2, 5, 10, 17, 34, 85

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 155 and 170. The biggest common factor number is the GCF number.
So the greatest common factor 155 and 170 is 5.

Also check out the Least Common Multiple of 155 and 170