Solution: The GCF of 65 and 33 is 1MethodsHow to find the GCF of 65 and 33 using Prime FactorizationOne way to find the GCF of 65 and 33 is to compare the prime factorization of each number. To find the prime factorization, you can follow the instructions for each number here:What are the Factors of 65?What are the Factors of 33?Here is the prime factorization of 65:51×1315^1 × 13^151×131And this is the prime factorization of 33:31×1113^1 × 11^131×111When you compare the prime factorization of these two numbers, you can see that there are no matching prime factors. When this is the case, it means that there are no common factors between these two numbers. As a result, the GCF of 65 and 33 is 1.Thus, the GCF of 65 and 33 is: 1How to Find the GCF of 65 and 33 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 65 and 33 is to find and list all the factors of each number. Again, you can see how this is done by looking at the “Factors of” articles that are linked to above.Let’s take a look at the factors for each of these numbers, 65 and 33:Factors of 65: 1, 5, 13, 65Factors of 33: 1, 3, 11, 33When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 65 and 33 is 1.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 44 and 46?What is the GCF of 78 and 146?What is the GCF of 68 and 88?What is the GCF of 30 and 136?What is the GCF of 19 and 104?