21978117

素因数分解:

$3^2\times 7^2\times {\mathrm{19}}^1\times {\mathrm{43}}^1\times {\mathrm{61}}^1$

素因数の和:143

約数の個数: 72

約数和(自身を含む): 40428960

約数和(自身を除く): 18450843

約数列:

[1, 3, 7, 9, 19, 21, 43, 49, 57, 61, 63, 129, 133, 147, 171, 183, 301, 387, 399, 427, 441, 549, 817, 903, 931, 1159, 1197, 1281, 2107, 2451, 2623, 2709, 2793, 2989, 3477, 3843, 5719, 6321, 7353, 7869, 8113, 8379, 8967, 10431, 17157, 18361, 18963, 23607, 24339, 26901, 40033, 49837, 51471, 55083, 56791, 73017, 120099, 128527, 149511, 165249, 170373, 348859, 360297, 385581, 448533, 511119, 1046577, 1156743, 2442013, 3139731, 7326039, 21978117]

約数ペア:

[(1, 21978117), (3, 7326039), (7, 3139731), (9, 2442013), (19, 1156743), (21, 1046577), (43, 511119), (49, 448533), (57, 385581), (61, 360297), (63, 348859), (129, 170373), (133, 165249), (147, 149511), (171, 128527), (183, 120099), (301, 73017), (387, 56791), (399, 55083), (427, 51471), (441, 49837), (549, 40033), (817, 26901), (903, 24339), (931, 23607), (1159, 18963), (1197, 18361), (1281, 17157), (2107, 10431), (2451, 8967), (2623, 8379), (2709, 8113), (2793, 7869), (2989, 7353), (3477, 6321), (3843, 5719)]