21278781

素因数分解:

$3^6\times {\mathrm{17}}^2\times {\mathrm{101}}^1$

素因数の和:153

約数の個数: 42

約数和(自身を含む): 34226202

約数和(自身を除く): 12947421

約数列:

[1, 3, 9, 17, 27, 51, 81, 101, 153, 243, 289, 303, 459, 729, 867, 909, 1377, 1717, 2601, 2727, 4131, 5151, 7803, 8181, 12393, 15453, 23409, 24543, 29189, 46359, 70227, 73629, 87567, 139077, 210681, 262701, 417231, 788103, 1251693, 2364309, 7092927, 21278781]

約数ペア:

[(1, 21278781), (3, 7092927), (9, 2364309), (17, 1251693), (27, 788103), (51, 417231), (81, 262701), (101, 210681), (153, 139077), (243, 87567), (289, 73629), (303, 70227), (459, 46359), (729, 29189), (867, 24543), (909, 23409), (1377, 15453), (1717, 12393), (2601, 8181), (2727, 7803), (4131, 5151)]