What is the Greatest Common Factor of 1221 and 1236?

Greatest common factor (GCF) of 1221 and 1236 is 3.

GCF(1221,1236) = 3

We will now calculate the prime factors of 1221 and 1236, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1221 and 1236.

How to find the GCF of 1221 and 1236?

We will first find the prime factorization of 1221 and 1236. After we will calculate the factors of 1221 and 1236 and find the biggest common factor number .

Step-1: Prime Factorization of 1221

Prime factors of 1221 are 3, 11, 37. Prime factorization of 1221 in exponential form is:

1221 = 3¹ × 11¹ × 37¹

Step-2: Prime Factorization of 1236

Prime factors of 1236 are 2, 3, 103. Prime factorization of 1236 in exponential form is:

1236 = 2² × 3¹ × 103¹

Step-3: Factors of 1221

List of positive integer factors of 1221 that divides 1221 without a remainder.

1, 3, 11, 33, 37, 111, 407

Step-4: Factors of 1236

List of positive integer factors of 1236 that divides 1221 without a remainder.

1, 2, 3, 4, 6, 12, 103, 206, 309, 412, 618

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1221 and 1236. The biggest common factor number is the GCF number.
So the greatest common factor 1221 and 1236 is 3.

Also check out the Least Common Multiple of 1221 and 1236