Greatest Common Factor of 14 and 19 = 1 Step 1: Find the prime factorization of 14 14 = 2 x 7 Step 2: Find the prime factorization of 19 19 = 19 Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf: GCF = = 1 Step 4: Therefore, the greatest common factor of 14 and 19 is 1.