20987980

素因数分解:

$2^2\times 5^1\times {\mathrm{13}}^1\times {\mathrm{89}}^1\times {\mathrm{907}}^1$

素因数の和:1018

約数の個数: 48

約数和(自身を含む): 48051360

約数和(自身を除く): 27063380

約数列:

[1, 2, 4, 5, 10, 13, 20, 26, 52, 65, 89, 130, 178, 260, 356, 445, 890, 907, 1157, 1780, 1814, 2314, 3628, 4535, 4628, 5785, 9070, 11570, 11791, 18140, 23140, 23582, 47164, 58955, 80723, 117910, 161446, 235820, 322892, 403615, 807230, 1049399, 1614460, 2098798, 4197596, 5246995, 10493990, 20987980]

約数ペア:

[(1, 20987980), (2, 10493990), (4, 5246995), (5, 4197596), (10, 2098798), (13, 1614460), (20, 1049399), (26, 807230), (52, 403615), (65, 322892), (89, 235820), (130, 161446), (178, 117910), (260, 80723), (356, 58955), (445, 47164), (890, 23582), (907, 23140), (1157, 18140), (1780, 11791), (1814, 11570), (2314, 9070), (3628, 5785), (4535, 4628)]