4
The smallest possible number to get from 3 and 4 as your factors is 12...
12
4 : with factors 1, 2 and 4
The smallest number that has exactly three factors is 4.
The factors of 4 are 1, 2, and 4 .
6. Factors are 1, 2, 3, and 6.
How about 6 whose factors are 1, 2, 3 and 6
That number is 60.
210 with factors of 2, 3, 5, and 7
6, with factors 1, 2, 3 and 6.
Logically, the smallest number with 4 different prime factors would have to be the product of the smallest four prime numbers. So the smallest natural number with four different prime factors is 210 (2*3*5*7).