47
48 has 10 factors, the most factors of any number under 50.
48 has the most factors..
45 has six factors.
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.
It is 30.
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.
45
48
The prime squares, like 4, 9, 25 and 49