What is the Greatest Common Factor of 78720 and 78740?

Greatest common factor (GCF) of 78720 and 78740 is 20.

GCF(78720,78740) = 20

We will now calculate the prime factors of 78720 and 78740, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 78720 and 78740.

How to find the GCF of 78720 and 78740?

We will first find the prime factorization of 78720 and 78740. After we will calculate the factors of 78720 and 78740 and find the biggest common factor number .

Step-1: Prime Factorization of 78720

Prime factors of 78720 are 2, 3, 5, 41. Prime factorization of 78720 in exponential form is:

78720 = 2⁷ × 3¹ × 5¹ × 41¹

Step-2: Prime Factorization of 78740

Prime factors of 78740 are 2, 5, 31, 127. Prime factorization of 78740 in exponential form is:

78740 = 2² × 5¹ × 31¹ × 127¹

Step-3: Factors of 78720

List of positive integer factors of 78720 that divides 78720 without a remainder.

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 32, 40, 41, 48, 60, 64, 80, 82, 96, 120, 123, 128, 160, 164, 192, 205, 240, 246, 320, 328, 384, 410, 480, 492, 615, 640, 656, 820, 960, 984, 1230, 1312, 1640, 1920, 1968, 2460, 2624, 3280, 3936, 4920, 5248, 6560, 7872, 9840, 13120, 15744, 19680, 26240, 39360

Step-4: Factors of 78740

List of positive integer factors of 78740 that divides 78720 without a remainder.

1, 2, 4, 5, 10, 20, 31, 62, 124, 127, 155, 254, 310, 508, 620, 635, 1270, 2540, 3937, 7874, 15748, 19685, 39370

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 78720 and 78740. The biggest common factor number is the GCF number.
So the greatest common factor 78720 and 78740 is 20.

Also check out the Least Common Multiple of 78720 and 78740