The factors of the number 8,406,684 are: 1, 2, 3, 4, 6, 9, 11, 12, 13, 18, 22, 23, 26, 33, 36, 39, 44, 46, 52, 66, 69, 71, 78, 92, 99, 117, 132, 138, 142, 143, 156, 198, 207, 213, 234, 253, 276, 284, 286, 299, 396, 414, 426, 429, 468, 506, 572, 598, 639, 759, 781, 828, 852, 858, 897, 923, 1012, 1196, 1278, 1287, 1518, 1562, 1633, 1716, 1794, 1846, 2277, 2343, 2556, 2574, 2691, 2769, 3036, 3124, 3266, 3289, 3588, 3692, 4554, 4686, 4899, 5148, 5382, 5538, 6532, 6578, 7029, 8307, 9108, 9372, 9798, 9867, 10153, 10764, 11076, 13156, 14058, 14697, 16614, 17963, 19596, 19734, 20306, 21229, 28116, 29394, 29601, 30459, 33228, 35926, 39468, 40612, 42458, 53889, 58788, 59202, 60918, 63687, 71852, 84916, 91377, 107778, 118404, 121836, 127374, 161667, 182754, 191061, 215556, 233519, 254748, 323334, 365508, 382122, 467038, 646668, 700557, 764244, 934076, 1401114, 2101671, 2802228, 4203342, 8406684.
If you add them up, you will get the total of 26,417,664.