Revisiting Inverses in Modular Arithmetic

Since 180 = 22 × 32 × 5, numbers less than 180 that are relatively prime to 180 are numbers not divisible by 2, 3, or 5. These are 1, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 77, and so on.