Solution: The GCF of 104 and 123 is 1MethodsHow to find the GCF of 104 and 123 using Prime FactorizationOne way to find the GCF of 104 and 123 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 104?What are the Factors of 123?Here is the prime factorization of 104:23×1312^3 × 13^123×131And this is the prime factorization of 123:31×4113^1 × 41^131×411When 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 104 and 123 is 1.Thus, the GCF of 104 and 123 is: 1How to Find the GCF of 104 and 123 by Listing All Common FactorsThe first step to this method of finding the Greatest Common Factor of 104 and 123 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, 104 and 123:Factors of 104: 1, 2, 4, 8, 13, 26, 52, 104Factors of 123: 1, 3, 41, 123When you compare the two lists of factors, you can see that the only common factor is 1. So, in this case, the GCF of 104 and 123 is 1.Find the GCF of Other Number PairsWant more practice? Try some of these other GCF problems:What is the GCF of 29 and 149?What is the GCF of 150 and 70?What is the GCF of 130 and 57?What is the GCF of 46 and 86?What is the GCF of 17 and 120?