What is the Greatest Common Factor of 285 and 289?

Greatest common factor (GCF) of 285 and 289 is 1.

GCF(285,289) = 1

We will now calculate the prime factors of 285 and 289, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 285 and 289.

How to find the GCF of 285 and 289?

We will first find the prime factorization of 285 and 289. After we will calculate the factors of 285 and 289 and find the biggest common factor number .

Step-1: Prime Factorization of 285

Prime factors of 285 are 3, 5, 19. Prime factorization of 285 in exponential form is:

285 = 3¹ × 5¹ × 19¹

Step-2: Prime Factorization of 289

Prime factors of 289 are 17. Prime factorization of 289 in exponential form is:

289 = 17²

Step-3: Factors of 285

List of positive integer factors of 285 that divides 285 without a remainder.

1, 3, 5, 15, 19, 57, 95

Step-4: Factors of 289

List of positive integer factors of 289 that divides 285 without a remainder.

1, 17

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 285 and 289. The biggest common factor number is the GCF number.
So the greatest common factor 285 and 289 is 1.

Also check out the Least Common Multiple of 285 and 289