What is the greatest common factor for 132 and 297?

The factors of 132 are: 1, 2, 3, 4, 6, 11, 12, 22, 33, 44, 66, 132

The factors of 297 are: 1, 3, 9, 11, 27, 33, 99, 297

The common factors are: 1, 3, 11, 33

The Greatest Common Factor (GCF) is: 33