21840

素因数分解:

$2^4\times 3^1\times 5^1\times 7^1\times {\mathrm{13}}^1$

素因数の和:36

約数の個数: 80

約数和(自身を含む): 83328

約数和(自身を除く): 61488

約数列:

[1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 13, 14, 15, 16, 20, 21, 24, 26, 28, 30, 35, 39, 40, 42, 48, 52, 56, 60, 65, 70, 78, 80, 84, 91, 104, 105, 112, 120, 130, 140, 156, 168, 182, 195, 208, 210, 240, 260, 273, 280, 312, 336, 364, 390, 420, 455, 520, 546, 560, 624, 728, 780, 840, 910, 1040, 1092, 1365, 1456, 1560, 1680, 1820, 2184, 2730, 3120, 3640, 4368, 5460, 7280, 10920, 21840]

約数ペア:

[(1, 21840), (2, 10920), (3, 7280), (4, 5460), (5, 4368), (6, 3640), (7, 3120), (8, 2730), (10, 2184), (12, 1820), (13, 1680), (14, 1560), (15, 1456), (16, 1365), (20, 1092), (21, 1040), (24, 910), (26, 840), (28, 780), (30, 728), (35, 624), (39, 560), (40, 546), (42, 520), (48, 455), (52, 420), (56, 390), (60, 364), (65, 336), (70, 312), (78, 280), (80, 273), (84, 260), (91, 240), (104, 210), (105, 208), (112, 195), (120, 182), (130, 168), (140, 156)]