Solution: The GCF of 133 and 5 is 1MethodsHow to find the GCF of 133 and 5 using Prime FactorizationOne way to find the GCF of 133 and 5 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 133?What are the Factors of 5?Here is the prime factorization of 133:71×1917^1 × 19^171×191And this is the prime factorization of 5:515^151When 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 133 and 5 is 1.Thus, the GCF of 133 and 5 is: 1How to Find the GCF of 133 and 5 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 133 and 5 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, 133 and 5:Factors of 133: 1, 7, 19, 133Factors of 5: 1, 5When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 133 and 5 is 1.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 28 and 123?What is the GCF of 149 and 7?What is the GCF of 138 and 4?What is the GCF of 90 and 139?What is the GCF of 97 and 75?