19780

素因数分解:

$2^2\times 5^1\times {\mathrm{23}}^1\times {\mathrm{43}}^1$

素因数の和:75

約数の個数: 24

約数和(自身を含む): 44352

約数和(自身を除く): 24572

約数列:

[1, 2, 4, 5, 10, 20, 23, 43, 46, 86, 92, 115, 172, 215, 230, 430, 460, 860, 989, 1978, 3956, 4945, 9890, 19780]

約数ペア:

[(1, 19780), (2, 9890), (4, 4945), (5, 3956), (10, 1978), (20, 989), (23, 860), (43, 460), (46, 430), (86, 230), (92, 215), (115, 172)]