21213981

素因数分解:

$3^4\times {\mathrm{23}}^1\times {\mathrm{59}}^1\times {\mathrm{193}}^1$

素因数の和:287

約数の個数: 40

約数和(自身を含む): 33802560

約数和(自身を除く): 12588579

約数列:

[1, 3, 9, 23, 27, 59, 69, 81, 177, 193, 207, 531, 579, 621, 1357, 1593, 1737, 1863, 4071, 4439, 4779, 5211, 11387, 12213, 13317, 15633, 34161, 36639, 39951, 102483, 109917, 119853, 261901, 307449, 359559, 785703, 922347, 2357109, 7071327, 21213981]

約数ペア:

[(1, 21213981), (3, 7071327), (9, 2357109), (23, 922347), (27, 785703), (59, 359559), (69, 307449), (81, 261901), (177, 119853), (193, 109917), (207, 102483), (531, 39951), (579, 36639), (621, 34161), (1357, 15633), (1593, 13317), (1737, 12213), (1863, 11387), (4071, 5211), (4439, 4779)]