47
48 has 10 factors, the most factors of any number under 50.
48 has the most factors..
45 has six factors.
It is 30.
Using "^" for powers. I believe the smallest ODD number with exactly 5 factors would be 3^4 = 81. Since you say "at least", we could also consider numbers with 6 factors; the smallest of those would be 3^2 x 5 = 45. So that would be a number under 50.
45
48
30
48
30
Every prime number has exactly two factors. They are '1' and the number itself. There are 15 prime numbers less than 50. A few of them are 2, 3, 5, 7, 11, 13, and 47.
The prime squares, like 4, 9, 25 and 49