640016

素因数分解:

$2^4\times {\mathrm{13}}^1\times {\mathrm{17}}^1\times {\mathrm{181}}^1$

素因数の和:219

約数の個数: 40

約数和(自身を含む): 1421784

約数和(自身を除く): 781768

約数列:

[1, 2, 4, 8, 13, 16, 17, 26, 34, 52, 68, 104, 136, 181, 208, 221, 272, 362, 442, 724, 884, 1448, 1768, 2353, 2896, 3077, 3536, 4706, 6154, 9412, 12308, 18824, 24616, 37648, 40001, 49232, 80002, 160004, 320008, 640016]

約数ペア:

[(1, 640016), (2, 320008), (4, 160004), (8, 80002), (13, 49232), (16, 40001), (17, 37648), (26, 24616), (34, 18824), (52, 12308), (68, 9412), (104, 6154), (136, 4706), (181, 3536), (208, 3077), (221, 2896), (272, 2353), (362, 1768), (442, 1448), (724, 884)]