21081320

素因数分解:

$2^3\times 5^1\times {\mathrm{13}}^1\times {\mathrm{71}}^1\times {\mathrm{571}}^1$

素因数の和:666

約数の個数: 64

約数和(自身を含む): 51891840

約数和(自身を除く): 30810520

約数列:

[1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 71, 104, 130, 142, 260, 284, 355, 520, 568, 571, 710, 923, 1142, 1420, 1846, 2284, 2840, 2855, 3692, 4568, 4615, 5710, 7384, 7423, 9230, 11420, 14846, 18460, 22840, 29692, 36920, 37115, 40541, 59384, 74230, 81082, 148460, 162164, 202705, 296920, 324328, 405410, 527033, 810820, 1054066, 1621640, 2108132, 2635165, 4216264, 5270330, 10540660, 21081320]

約数ペア:

[(1, 21081320), (2, 10540660), (4, 5270330), (5, 4216264), (8, 2635165), (10, 2108132), (13, 1621640), (20, 1054066), (26, 810820), (40, 527033), (52, 405410), (65, 324328), (71, 296920), (104, 202705), (130, 162164), (142, 148460), (260, 81082), (284, 74230), (355, 59384), (520, 40541), (568, 37115), (571, 36920), (710, 29692), (923, 22840), (1142, 18460), (1420, 14846), (1846, 11420), (2284, 9230), (2840, 7423), (2855, 7384), (3692, 5710), (4568, 4615)]