The factors of the number 6,531,264 are: 1, 2, 3, 4, 6, 8, 9, 12, 16, 17, 18, 23, 24, 29, 32, 34, 36, 46, 48, 51, 58, 64, 68, 69, 72, 87, 92, 96, 102, 116, 136, 138, 144, 153, 174, 184, 192, 204, 207, 232, 261, 272, 276, 288, 306, 348, 368, 391, 408, 414, 464, 493, 522, 544, 552, 576, 612, 667, 696, 736, 782, 816, 828, 928, 986, 1044, 1088, 1104, 1173, 1224, 1334, 1392, 1472, 1479, 1564, 1632, 1656, 1856, 1972, 2001, 2088, 2208, 2346, 2448, 2668, 2784, 2958, 3128, 3264, 3312, 3519, 3944, 4002, 4176, 4416, 4437, 4692, 4896, 5336, 5568, 5916, 6003, 6256, 6624, 7038, 7888, 8004, 8352, 8874, 9384, 9792, 10672, 11339, 11832, 12006, 12512, 13248, 14076, 15776, 16008, 16704, 17748, 18768, 21344, 22678, 23664, 24012, 25024, 28152, 31552, 32016, 34017, 35496, 37536, 42688, 45356, 47328, 48024, 56304, 64032, 68034, 70992, 75072, 90712, 94656, 96048, 102051, 112608, 128064, 136068, 141984, 181424, 192096, 204102, 225216, 272136, 283968, 362848, 384192, 408204, 544272, 725696, 816408, 1088544, 1632816, 2177088, 3265632, 6531264.
If you add them up, you will get the total of 21,396,960.