20991855

素因数分解:

$3^1\times 5^1\times {\mathrm{17}}^1\times {\mathrm{191}}^1\times {\mathrm{431}}^1$

素因数の和:647

約数の個数: 32

約数和(自身を含む): 35831808

約数和(自身を除く): 14839953

約数列:

[1, 3, 5, 15, 17, 51, 85, 191, 255, 431, 573, 955, 1293, 2155, 2865, 3247, 6465, 7327, 9741, 16235, 21981, 36635, 48705, 82321, 109905, 246963, 411605, 1234815, 1399457, 4198371, 6997285, 20991855]

約数ペア:

[(1, 20991855), (3, 6997285), (5, 4198371), (15, 1399457), (17, 1234815), (51, 411605), (85, 246963), (191, 109905), (255, 82321), (431, 48705), (573, 36635), (955, 21981), (1293, 16235), (2155, 9741), (2865, 7327), (3247, 6465)]