Visual Factor Pairs
Prime Numbers- can only be divided by themselves and 1.
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239
Semiprime Numbers -exactly two prime factors.
4 (2 × 2)
6 (2 × 3)
9 (3 × 3)
10 (2 × 5)
14 (2 × 7)
15 (3 × 5)
21 (3 × 7)
22 (2 × 11)
25 (5 × 5)
26 (2 × 13)
33 (3 × 11)
34 (2 × 17)
35 (5 × 7)
49 (7 × 7)
...
Triprime Numbers -exactly three prime factors.
8 (2, 2, 2)
12 (2, 2, 3)
27 (3, 3, 3)
30 (2, 3, 5)
42 (2, 3, 7)
66 (2, 3, 11)
70 (2, 5, 7)
78 (2, 3, 13)
102 (2, 3, 17)
110 (2, 5, 11)
114 (2, 3, 19)
138 (2, 3, 23)
154 (2, 7, 11)
...