19991991

素因数分解:

$3^1\times {\mathrm{23}}^1\times {\mathrm{29}}^1\times {\mathrm{97}}^1\times {\mathrm{103}}^1$

素因数の和:255

約数の個数: 32

約数和(自身を含む): 29352960

約数和(自身を除く): 9360969

約数列:

[1, 3, 23, 29, 69, 87, 97, 103, 291, 309, 667, 2001, 2231, 2369, 2813, 2987, 6693, 7107, 8439, 8961, 9991, 29973, 64699, 68701, 194097, 206103, 229793, 289739, 689379, 869217, 6663997, 19991991]

約数ペア:

[(1, 19991991), (3, 6663997), (23, 869217), (29, 689379), (69, 289739), (87, 229793), (97, 206103), (103, 194097), (291, 68701), (309, 64699), (667, 29973), (2001, 9991), (2231, 8961), (2369, 8439), (2813, 7107), (2987, 6693)]