4digit number
The biggest odd number between 1 and 10 is 9.
There is no biggest 5 odd number since a number that is two more will be bigger still.
5295
It is 1,000.
9000
1000
That's just as meaningless a question as asking "what is the biggest number?" Just as there is no biggest number (you can always get bigger numbers by adding 1), there is no odd number with the most factors. You could multiply any odd number by 3, and get an odd number with another factor of 3.
9999
9
9825
87543001