21091220

素因数分解:

$2^2\times 5^1\times {\mathrm{17}}^2\times {\mathrm{41}}^1\times {\mathrm{89}}^1$

素因数の和:173

約数の個数: 72

約数和(自身を含む): 48739320

約数和(自身を除く): 27648100

約数列:

[1, 2, 4, 5, 10, 17, 20, 34, 41, 68, 82, 85, 89, 164, 170, 178, 205, 289, 340, 356, 410, 445, 578, 697, 820, 890, 1156, 1394, 1445, 1513, 1780, 2788, 2890, 3026, 3485, 3649, 5780, 6052, 6970, 7298, 7565, 11849, 13940, 14596, 15130, 18245, 23698, 25721, 30260, 36490, 47396, 51442, 59245, 62033, 72980, 102884, 118490, 124066, 128605, 236980, 248132, 257210, 310165, 514420, 620330, 1054561, 1240660, 2109122, 4218244, 5272805, 10545610, 21091220]

約数ペア:

[(1, 21091220), (2, 10545610), (4, 5272805), (5, 4218244), (10, 2109122), (17, 1240660), (20, 1054561), (34, 620330), (41, 514420), (68, 310165), (82, 257210), (85, 248132), (89, 236980), (164, 128605), (170, 124066), (178, 118490), (205, 102884), (289, 72980), (340, 62033), (356, 59245), (410, 51442), (445, 47396), (578, 36490), (697, 30260), (820, 25721), (890, 23698), (1156, 18245), (1394, 15130), (1445, 14596), (1513, 13940), (1780, 11849), (2788, 7565), (2890, 7298), (3026, 6970), (3485, 6052), (3649, 5780)]