What is the Greatest Common Factor of 390 and 403?

Greatest common factor (GCF) of 390 and 403 is 13.

GCF(390,403) = 13

We will now calculate the prime factors of 390 and 403, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 390 and 403.

How to find the GCF of 390 and 403?

We will first find the prime factorization of 390 and 403. After we will calculate the factors of 390 and 403 and find the biggest common factor number .

Step-1: Prime Factorization of 390

Prime factors of 390 are 2, 3, 5, 13. Prime factorization of 390 in exponential form is:

390 = 2¹ × 3¹ × 5¹ × 13¹

Step-2: Prime Factorization of 403

Prime factors of 403 are 13, 31. Prime factorization of 403 in exponential form is:

403 = 13¹ × 31¹

Step-3: Factors of 390

List of positive integer factors of 390 that divides 390 without a remainder.

1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195

Step-4: Factors of 403

List of positive integer factors of 403 that divides 390 without a remainder.

1, 13, 31

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 390 and 403. The biggest common factor number is the GCF number.
So the greatest common factor 390 and 403 is 13.

Also check out the Least Common Multiple of 390 and 403