21278140

素因数分解:

$2^2\times 5^1\times {\mathrm{13}}^1\times {\mathrm{81839}}^1$

素因数の和:81861

約数の個数: 24

約数和(自身を含む): 48121920

約数和(自身を除く): 26843780

約数列:

[1, 2, 4, 5, 10, 13, 20, 26, 52, 65, 130, 260, 81839, 163678, 327356, 409195, 818390, 1063907, 1636780, 2127814, 4255628, 5319535, 10639070, 21278140]

約数ペア:

[(1, 21278140), (2, 10639070), (4, 5319535), (5, 4255628), (10, 2127814), (13, 1636780), (20, 1063907), (26, 818390), (52, 409195), (65, 327356), (130, 163678), (260, 81839)]