21005973

素因数分解:

$3^4\times {\mathrm{37}}^1\times {\mathrm{43}}^1\times {\mathrm{163}}^1$

素因数の和:255

約数の個数: 40

約数和(自身を含む): 33179168

約数和(自身を除く): 12173195

約数列:

[1, 3, 9, 27, 37, 43, 81, 111, 129, 163, 333, 387, 489, 999, 1161, 1467, 1591, 2997, 3483, 4401, 4773, 6031, 7009, 13203, 14319, 18093, 21027, 42957, 54279, 63081, 128871, 162837, 189243, 259333, 488511, 567729, 777999, 2333997, 7001991, 21005973]

約数ペア:

[(1, 21005973), (3, 7001991), (9, 2333997), (27, 777999), (37, 567729), (43, 488511), (81, 259333), (111, 189243), (129, 162837), (163, 128871), (333, 63081), (387, 54279), (489, 42957), (999, 21027), (1161, 18093), (1467, 14319), (1591, 13203), (2997, 7009), (3483, 6031), (4401, 4773)]