The factors of the number 644,056,336 are: 1, 2, 4, 7, 8, 11, 14, 16, 22, 28, 37, 44, 56, 71, 74, 77, 88, 112, 142, 148, 154, 176, 199, 259, 284, 296, 308, 398, 407, 497, 518, 568, 592, 616, 781, 796, 814, 994, 1036, 1136, 1232, 1393, 1562, 1592, 1628, 1988, 2072, 2189, 2627, 2786, 2849, 3124, 3184, 3256, 3976, 4144, 4378, 5254, 5467, 5572, 5698, 6248, 6512, 7363, 7952, 8756, 10508, 10934, 11144, 11396, 12496, 14129, 14726, 15323, 17512, 18389, 21016, 21868, 22288, 22792, 28258, 28897, 29452, 30646, 35024, 36778, 42032, 43736, 45584, 51541, 56516, 57794, 58904, 61292, 73556, 80993, 87472, 98903, 103082, 113032, 115588, 117808, 122584, 147112, 155419, 161986, 197806, 202279, 206164, 226064, 231176, 245168, 294224, 310838, 323972, 395612, 404558, 412328, 462352, 522773, 566951, 621676, 647944, 791224, 809116, 824656, 1045546, 1087933, 1133902, 1243352, 1295888, 1582448, 1618232, 2091092, 2175866, 2267804, 2486704, 3236464, 3659411, 4182184, 4351732, 4535608, 5750503, 7318822, 8364368, 8703464, 9071216, 11501006, 14637644, 17406928, 23002012, 29275288, 40253521, 46004024, 58550576, 80507042, 92008048, 161014084, 322028168, 644056336.
If you add them up, you will get the total of 1,628,467,200.