GCF for 81 and 243

What is the Greatest common Divisor of 81 and 243?

Answer: GCF of 81 and 243 is 81

(Eighty-one)

Finding GCF for 81 and 243 using all factors (divisors) listing

The first method to find GCF for numbers 81 and 243 is to list all factors for both numbers and pick the highest common one:

All factors of 81: 1, 3, 9, 27, 81

All factors of 243: 1, 3, 9, 27, 81, 243

So the Greatest Common Factor for 81 and 243 is 81

Finding GCF for 81 and 243 by Prime Factorization

The second method to find GCF for numbers 81 and 243 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 81: 3, 3, 3, 3

All Prime Factors of 243: 3, 3, 3, 3, 3

As we can see there are Prime Factors common to both numbers: 3, 3, 3, 3

Now we need to multiply them to find GCF: 3 × 3 × 3 × 3 = 81

GCF Table

Number 1Number 2GCF
662433
672431
682431
692433
702431
712431
722439
732431
742431
752433
762431
772431
782433
792431
802431
81243
822431
832431
842433
852431
862431
872433
882431
892431
902439
912431
922431
932433
942431
952431

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest common Divisor of 81 and 243? (The answer is: 81). Select the first number (e.g. '81') and the second number (e.g. '243'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest common Divisor of 81 and 243?

GCF of 81 and 243 is 81