The factors of the number 6,635,304 are: 1, 2, 3, 4, 6, 8, 9, 12, 13, 17, 18, 24, 26, 27, 34, 36, 39, 51, 52, 54, 68, 72, 78, 102, 104, 108, 117, 136, 139, 153, 156, 204, 216, 221, 234, 278, 306, 312, 351, 408, 417, 442, 459, 468, 556, 612, 663, 702, 834, 884, 918, 936, 1112, 1224, 1251, 1326, 1404, 1668, 1768, 1807, 1836, 1989, 2363, 2502, 2652, 2808, 3336, 3614, 3672, 3753, 3978, 4726, 5004, 5304, 5421, 5967, 7089, 7228, 7506, 7956, 9452, 10008, 10842, 11934, 14178, 14456, 15012, 15912, 16263, 18904, 21267, 21684, 23868, 28356, 30024, 30719, 32526, 42534, 43368, 47736, 48789, 56712, 61438, 63801, 65052, 85068, 92157, 97578, 122876, 127602, 130104, 170136, 184314, 195156, 245752, 255204, 276471, 368628, 390312, 510408, 552942, 737256, 829413, 1105884, 1658826, 2211768, 3317652, 6635304.
If you add them up, you will get the total of 21,168,000.