21的因數:(1,3,7,21)
22的因數:(1,2,11,22)
24的因數:(1,2,3,4,6,8,12,24)
25的因數:(1,5,25)
26的因數:(1,2,13,26)
27的因數:(1,3,9,27)
28的因數:(1,2,4,7,14,28)
30的因數:(1,2,3,5,6,10,15,30)
32的因數:(1,2,4,8,16,32)
33的因數:(1,3,11,33)
34的因數:(1,2,17,34)
35的因數:(1,5,7,35)
36的因數:(1,2,3,4,9,12,18,36)
38的因數:(1,2,19,38)
39的因數:(1,3,13,39)
40的因數:(1,2,4,5,8,10,20 ,40)
42的因數:(1,2,3,6,7,14,21,42)
44的因數:(1,2,4,11,22,44)
45的因數:(1,3,5,9,15,45)
46的因數:(1,2,23,46)
48的因數:(1,2,3,4,6,8,12,16,24,48)
49的因數:(1,7,49)
50的因數:(1,2,5,10,25,50)
51的因數:(1,17,3,51)
52的因數:(1,2,4,13,26,52)
54的因數:(1,2,3,6,9,18,27,54)
55的因數:(1,5,11,55)
56的因數:(1,2,4,7,8,14,28,56)
58的因數:(1,2,29,58)
60的因數:(1,2,3,4,5,6,10,12,15,20,30,60)
62的因數:(1,2,31,62)
63的因數:(1,3,7,9,21,63)
64的因數:(1,2,4,8,16,32,64)
65的因數:(1,5,13,65)
66的因數:(1,2,3,6,11,22,33,66)
68的因數:(1,2,4,17,34,68)
69的因數:(1,3,23,69)
70的因數:(1,2,5,7,10,14,35,70)
72的因數:(1,2,3,4,6,8,9,12,18,24,36,72)
74的因數:(1,2,37,74)
75的因數:(1,3,5,15,25,75)
76的因數:(1,2,4,19,38,76)
77的因數:(1,7,11,77)
78的因數:(1,2,3,6,13,26,39,78)
80的因數:(1,2,4,5,8,10,16,20,40,80)