Well, darling, the number you're looking for is 15. It's less than 20, odd, and can be broken down into the prime factors 3 and 5. So, there you have it, a prime factor party with the number 15 strutting its stuff.
Prime numbers
All of the numbers less than 100 (except for -1, 0 and 1) have prime factors. I suspect you left some qualifying information out of your question.
Here are all the prime numbers less than 12: 2, 3, 5, 7, 11
If you're allowed to repeat factors, 2 x 2 x 2 x 2 = 16. If not, no number less than 100 has more than 3 distinct prime factors.
By definition, a prime number has exactly two factors. So, there are no prime numbers with exactly three factors.
A number is prime if its only two factors are one and itself.
512 = 29 or 768 = 28*3 have 9 prime factors each.
2 and 7 are prime numbers less than 10 that are factors of 42 and 70.
They all are prime numbers except 1
2, 3 and 7
30