20997808

素因数分解:

$2^4\times {\mathrm{13}}^1\times {\mathrm{157}}^1\times {\mathrm{643}}^1$

素因数の和:821

約数の個数: 40

約数和(自身を含む): 44160368

約数和(自身を除く): 23162560

約数列:

[1, 2, 4, 8, 13, 16, 26, 52, 104, 157, 208, 314, 628, 643, 1256, 1286, 2041, 2512, 2572, 4082, 5144, 8164, 8359, 10288, 16328, 16718, 32656, 33436, 66872, 100951, 133744, 201902, 403804, 807608, 1312363, 1615216, 2624726, 5249452, 10498904, 20997808]

約数ペア:

[(1, 20997808), (2, 10498904), (4, 5249452), (8, 2624726), (13, 1615216), (16, 1312363), (26, 807608), (52, 403804), (104, 201902), (157, 133744), (208, 100951), (314, 66872), (628, 33436), (643, 32656), (1256, 16718), (1286, 16328), (2041, 10288), (2512, 8359), (2572, 8164), (4082, 5144)]