21780380

素因数分解:

$2^2\times 5^1\times {\mathrm{97}}^1\times {\mathrm{103}}^1\times {\mathrm{109}}^1$

素因数の和:318

約数の個数: 48

約数和(自身を含む): 47087040

約数和(自身を除く): 25306660

約数列:

[1, 2, 4, 5, 10, 20, 97, 103, 109, 194, 206, 218, 388, 412, 436, 485, 515, 545, 970, 1030, 1090, 1940, 2060, 2180, 9991, 10573, 11227, 19982, 21146, 22454, 39964, 42292, 44908, 49955, 52865, 56135, 99910, 105730, 112270, 199820, 211460, 224540, 1089019, 2178038, 4356076, 5445095, 10890190, 21780380]

約数ペア:

[(1, 21780380), (2, 10890190), (4, 5445095), (5, 4356076), (10, 2178038), (20, 1089019), (97, 224540), (103, 211460), (109, 199820), (194, 112270), (206, 105730), (218, 99910), (388, 56135), (412, 52865), (436, 49955), (485, 44908), (515, 42292), (545, 39964), (970, 22454), (1030, 21146), (1090, 19982), (1940, 11227), (2060, 10573), (2180, 9991)]