The factors of the number 320,405,400 are: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 21, 24, 25, 28, 30, 35, 36, 40, 42, 45, 50, 56, 59, 60, 63, 70, 72, 75, 84, 90, 100, 105, 118, 120, 126, 140, 150, 168, 175, 177, 180, 200, 210, 225, 236, 252, 280, 295, 300, 315, 350, 354, 360, 413, 420, 431, 450, 472, 504, 525, 531, 590, 600, 630, 700, 708, 826, 840, 862, 885, 900, 1050, 1062, 1180, 1239, 1260, 1293, 1400, 1416, 1475, 1575, 1652, 1724, 1770, 1800, 2065, 2100, 2124, 2155, 2360, 2478, 2520, 2586, 2655, 2950, 3017, 3150, 3304, 3448, 3540, 3717, 3879, 4130, 4200, 4248, 4310, 4425, 4956, 5172, 5310, 5900, 6034, 6195, 6300, 6465, 7080, 7434, 7758, 8260, 8620, 8850, 9051, 9912, 10325, 10344, 10620, 10775, 11800, 12068, 12390, 12600, 12930, 13275, 14868, 15085, 15516, 16520, 17240, 17700, 18102, 18585, 19395, 20650, 21240, 21550, 24136, 24780, 25429, 25860, 26550, 27153, 29736, 30170, 30975, 31032, 32325, 35400, 36204, 37170, 38790, 41300, 43100, 45255, 49560, 50858, 51720, 53100, 54306, 60340, 61950, 64650, 72408, 74340, 75425, 76287, 77580, 82600, 86200, 90510, 92925, 96975, 101716, 106200, 108612, 120680, 123900, 127145, 129300, 135765, 148680, 150850, 152574, 155160, 178003, 181020, 185850, 193950, 203432, 217224, 226275, 228861, 247800, 254290, 258600, 271530, 301700, 305148, 356006, 362040, 371700, 381435, 387900, 452550, 457722, 508580, 534009, 543060, 603400, 610296, 635725, 678825, 712012, 743400, 762870, 775800, 890015, 905100, 915444, 1017160, 1068018, 1086120, 1144305, 1271450, 1357650, 1424024, 1525740, 1602027, 1780030, 1810200, 1830888, 1907175, 2136036, 2288610, 2542900, 2670045, 2715300, 3051480, 3204054, 3560060, 3814350, 4272072, 4450075, 4577220, 5085800, 5340090, 5430600, 5721525, 6408108, 7120120, 7628700, 8010135, 8900150, 9154440, 10680180, 11443050, 12816216, 13350225, 15257400, 16020270, 17800300, 21360360, 22886100, 26700450, 32040540, 35600600, 40050675, 45772200, 53400900, 64081080, 80101350, 106801800, 160202700, 320405400.
If you add them up, you will get the total of 1,253,491,200.