I'm assuming the answer has to be whole, and there aren't any loopholes such as negative numbers.
Answer:
It should be 6 because 6/6=1 and 6/3=2.
To check, go through smaller numbers than the one you found and divide.
Check:
5/6 = 0.84 - isn't whole
4/6 = 0.7 - isn't whole
3/6 = 0.5 - isn't whole
2/6 = 0.4 - isn't whole
1/6 = 0.2 - Isn't whole*
Anyways, the answer is 6
*these are rounded to the nearest tenth*