21420

素因数分解:

$2^2\times 3^2\times 5^1\times 7^1\times {\mathrm{17}}^1$

素因数の和:39

約数の個数: 72

約数和(自身を含む): 78624

約数和(自身を除く): 57204

約数列:

[1, 2, 3, 4, 5, 6, 7, 9, 10, 12, 14, 15, 17, 18, 20, 21, 28, 30, 34, 35, 36, 42, 45, 51, 60, 63, 68, 70, 84, 85, 90, 102, 105, 119, 126, 140, 153, 170, 180, 204, 210, 238, 252, 255, 306, 315, 340, 357, 420, 476, 510, 595, 612, 630, 714, 765, 1020, 1071, 1190, 1260, 1428, 1530, 1785, 2142, 2380, 3060, 3570, 4284, 5355, 7140, 10710, 21420]

約数ペア:

[(1, 21420), (2, 10710), (3, 7140), (4, 5355), (5, 4284), (6, 3570), (7, 3060), (9, 2380), (10, 2142), (12, 1785), (14, 1530), (15, 1428), (17, 1260), (18, 1190), (20, 1071), (21, 1020), (28, 765), (30, 714), (34, 630), (35, 612), (36, 595), (42, 510), (45, 476), (51, 420), (60, 357), (63, 340), (68, 315), (70, 306), (84, 255), (85, 252), (90, 238), (102, 210), (105, 204), (119, 180), (126, 170), (140, 153)]