12 = 2 * 6 = 2 * 2 * 3 ------------------------- 42 = 2 * 21 = 2 * 3 * 7 ------------------------- 216 = 2 * 108 = 2 * 2 * 54 = 2 * 2 * 2 * 27 = 2 * 2 * 2 * 3 * 3 * 3 -------------------------- 920 = 2 * 460 = 2 * 2 * 230 = 2 * 2 * 2 * 115 = 2 * 2 * 2 * 5 * 23 --------------------------- 2280 = 2 * 1140 = 2 * 2 * 570 = 2 * 2 * 2 * 285 = 2 * 2 * 2 * 57 * 5 = = 2 * 2 * 2 * 5 * 3 * 19 ----------------------------- 10850 = 2 * 5425 = 2 * 5 * 1085 = 2 * 5 * 5 * 217 = 2 * 5 * 5 * 7 * 31