Factorization
220 = 2 × 2 × 5 × 11
220 has 12 divisors: 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, 220
Sum of all divisors other than 220:
284
Sums & differences
Difference of 2 squares: 220 = 162 - 62 = 562 - 542
Goldbach conjecture: 220 = 197 + 23 = 191 + 29 = 179 + 41 = 173 + 47 = 167 + 53 = 149 + 71 = 137 + 83 = 131 + 89 = 113 + 107
