21405951

素因数分解:

$3^4\times 7^1\times {\mathrm{19}}^1\times {\mathrm{1987}}^1$

素因数の和:2025

約数の個数: 40

約数和(自身を含む): 38487680

約数和(自身を除く): 17081729

約数列:

[1, 3, 7, 9, 19, 21, 27, 57, 63, 81, 133, 171, 189, 399, 513, 567, 1197, 1539, 1987, 3591, 5961, 10773, 13909, 17883, 37753, 41727, 53649, 113259, 125181, 160947, 264271, 339777, 375543, 792813, 1019331, 1126629, 2378439, 3057993, 7135317, 21405951]

約数ペア:

[(1, 21405951), (3, 7135317), (7, 3057993), (9, 2378439), (19, 1126629), (21, 1019331), (27, 792813), (57, 375543), (63, 339777), (81, 264271), (133, 160947), (171, 125181), (189, 113259), (399, 53649), (513, 41727), (567, 37753), (1197, 17883), (1539, 13909), (1987, 10773), (3591, 5961)]