Question: what is the greatest common factor of 18?
Answer: Example: Find the GCF of 18 and 27 The factors of 18 are 1, 2, 3, 6, 9, 18. The factors of 27 are 1, 3, 9, 27. The common factors of 18 and 27 are 1, 3 and 9. The greatest common factor of 18 and 27 is 9.