The factors of the number 4,120,956 are: 1, 2, 3, 4, 6, 7, 9, 12, 14, 18, 21, 23, 27, 28, 36, 42, 46, 54, 63, 69, 79, 81, 84, 92, 108, 126, 138, 158, 161, 162, 189, 207, 237, 252, 276, 316, 322, 324, 378, 414, 474, 483, 553, 567, 621, 644, 711, 756, 828, 948, 966, 1106, 1134, 1242, 1422, 1449, 1659, 1817, 1863, 1932, 2133, 2212, 2268, 2484, 2844, 2898, 3318, 3634, 3726, 4266, 4347, 4977, 5451, 5796, 6399, 6636, 7268, 7452, 8532, 8694, 9954, 10902, 12719, 12798, 13041, 14931, 16353, 17388, 19908, 21804, 25438, 25596, 26082, 29862, 32706, 38157, 44793, 49059, 50876, 52164, 59724, 65412, 76314, 89586, 98118, 114471, 147177, 152628, 179172, 196236, 228942, 294354, 343413, 457884, 588708, 686826, 1030239, 1373652, 2060478, 4120956.
If you add them up, you will get the total of 13,009,920.