21438940

素因数分解:

$2^2\times 5^1\times {\mathrm{43}}^1\times {\mathrm{97}}^1\times {\mathrm{257}}^1$

素因数の和:406

約数の個数: 48

約数和(自身を含む): 46724832

約数和(自身を除く): 25285892

約数列:

[1, 2, 4, 5, 10, 20, 43, 86, 97, 172, 194, 215, 257, 388, 430, 485, 514, 860, 970, 1028, 1285, 1940, 2570, 4171, 5140, 8342, 11051, 16684, 20855, 22102, 24929, 41710, 44204, 49858, 55255, 83420, 99716, 110510, 124645, 221020, 249290, 498580, 1071947, 2143894, 4287788, 5359735, 10719470, 21438940]

約数ペア:

[(1, 21438940), (2, 10719470), (4, 5359735), (5, 4287788), (10, 2143894), (20, 1071947), (43, 498580), (86, 249290), (97, 221020), (172, 124645), (194, 110510), (215, 99716), (257, 83420), (388, 55255), (430, 49858), (485, 44204), (514, 41710), (860, 24929), (970, 22102), (1028, 20855), (1285, 16684), (1940, 11051), (2570, 8342), (4171, 5140)]