21989720

素因数分解:

$2^3\times 5^1\times {\mathrm{101}}^1\times {\mathrm{5443}}^1$

素因数の和:5555

約数の個数: 32

約数和(自身を含む): 49975920

約数和(自身を除く): 27986200

約数列:

[1, 2, 4, 5, 8, 10, 20, 40, 101, 202, 404, 505, 808, 1010, 2020, 4040, 5443, 10886, 21772, 27215, 43544, 54430, 108860, 217720, 549743, 1099486, 2198972, 2748715, 4397944, 5497430, 10994860, 21989720]

約数ペア:

[(1, 21989720), (2, 10994860), (4, 5497430), (5, 4397944), (8, 2748715), (10, 2198972), (20, 1099486), (40, 549743), (101, 217720), (202, 108860), (404, 54430), (505, 43544), (808, 27215), (1010, 21772), (2020, 10886), (4040, 5443)]