21388880

素因数分解:

$2^4\times 5^1\times {\mathrm{41}}^1\times {\mathrm{6521}}^1$

素因数の和:6575

約数の個数: 40

約数和(自身を含む): 50949864

約数和(自身を除く): 29560984

約数列:

[1, 2, 4, 5, 8, 10, 16, 20, 40, 41, 80, 82, 164, 205, 328, 410, 656, 820, 1640, 3280, 6521, 13042, 26084, 32605, 52168, 65210, 104336, 130420, 260840, 267361, 521680, 534722, 1069444, 1336805, 2138888, 2673610, 4277776, 5347220, 10694440, 21388880]

約数ペア:

[(1, 21388880), (2, 10694440), (4, 5347220), (5, 4277776), (8, 2673610), (10, 2138888), (16, 1336805), (20, 1069444), (40, 534722), (41, 521680), (80, 267361), (82, 260840), (164, 130420), (205, 104336), (328, 65210), (410, 52168), (656, 32605), (820, 26084), (1640, 13042), (3280, 6521)]