21078760

素因数分解:

$2^3\times 5^1\times {\mathrm{31}}^1\times {\mathrm{89}}^1\times {\mathrm{191}}^1$

素因数の和:322

約数の個数: 64

約数和(自身を含む): 49766400

約数和(自身を除く): 28687640

約数列:

[1, 2, 4, 5, 8, 10, 20, 31, 40, 62, 89, 124, 155, 178, 191, 248, 310, 356, 382, 445, 620, 712, 764, 890, 955, 1240, 1528, 1780, 1910, 2759, 3560, 3820, 5518, 5921, 7640, 11036, 11842, 13795, 16999, 22072, 23684, 27590, 29605, 33998, 47368, 55180, 59210, 67996, 84995, 110360, 118420, 135992, 169990, 236840, 339980, 526969, 679960, 1053938, 2107876, 2634845, 4215752, 5269690, 10539380, 21078760]

約数ペア:

[(1, 21078760), (2, 10539380), (4, 5269690), (5, 4215752), (8, 2634845), (10, 2107876), (20, 1053938), (31, 679960), (40, 526969), (62, 339980), (89, 236840), (124, 169990), (155, 135992), (178, 118420), (191, 110360), (248, 84995), (310, 67996), (356, 59210), (382, 55180), (445, 47368), (620, 33998), (712, 29605), (764, 27590), (890, 23684), (955, 22072), (1240, 16999), (1528, 13795), (1780, 11842), (1910, 11036), (2759, 7640), (3560, 5921), (3820, 5518)]