21128120

素因数分解:

$2^3\times 5^1\times {\mathrm{13}}^1\times {\mathrm{41}}^1\times {\mathrm{991}}^1$

素因数の和:1056

約数の個数: 64

約数和(自身を含む): 52496640

約数和(自身を除く): 31368520

約数列:

[1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 41, 52, 65, 82, 104, 130, 164, 205, 260, 328, 410, 520, 533, 820, 991, 1066, 1640, 1982, 2132, 2665, 3964, 4264, 4955, 5330, 7928, 9910, 10660, 12883, 19820, 21320, 25766, 39640, 40631, 51532, 64415, 81262, 103064, 128830, 162524, 203155, 257660, 325048, 406310, 515320, 528203, 812620, 1056406, 1625240, 2112812, 2641015, 4225624, 5282030, 10564060, 21128120]

約数ペア:

[(1, 21128120), (2, 10564060), (4, 5282030), (5, 4225624), (8, 2641015), (10, 2112812), (13, 1625240), (20, 1056406), (26, 812620), (40, 528203), (41, 515320), (52, 406310), (65, 325048), (82, 257660), (104, 203155), (130, 162524), (164, 128830), (205, 103064), (260, 81262), (328, 64415), (410, 51532), (520, 40631), (533, 39640), (820, 25766), (991, 21320), (1066, 19820), (1640, 12883), (1982, 10660), (2132, 9910), (2665, 7928), (3964, 5330), (4264, 4955)]