21990315

素因数分解:

$3^1\times 5^1\times {\mathrm{19}}^2\times {\mathrm{31}}^1\times {\mathrm{131}}^1$

素因数の和:208

約数の個数: 48

約数和(自身を含む): 38624256

約数和(自身を除く): 16633941

約数列:

[1, 3, 5, 15, 19, 31, 57, 93, 95, 131, 155, 285, 361, 393, 465, 589, 655, 1083, 1767, 1805, 1965, 2489, 2945, 4061, 5415, 7467, 8835, 11191, 12183, 12445, 20305, 33573, 37335, 47291, 55955, 60915, 77159, 141873, 167865, 231477, 236455, 385795, 709365, 1157385, 1466021, 4398063, 7330105, 21990315]

約数ペア:

[(1, 21990315), (3, 7330105), (5, 4398063), (15, 1466021), (19, 1157385), (31, 709365), (57, 385795), (93, 236455), (95, 231477), (131, 167865), (155, 141873), (285, 77159), (361, 60915), (393, 55955), (465, 47291), (589, 37335), (655, 33573), (1083, 20305), (1767, 12445), (1805, 12183), (1965, 11191), (2489, 8835), (2945, 7467), (4061, 5415)]