What are the common factors of 220 and 284?

The common factors of 220 and 284 are the numbers that can evenly divide both 220 and 284 without leaving a remainder. To find the common factors, we first need to find the prime factorization of each number. The prime factorization of 220 is 2^2 * 5 * 11, and the prime factorization of 284 is 2^2 * 71. The common factors of 220 and 284 are the numbers that appear in both factorizations, which are 2 and 4.