Question 1200715
<font color=black size=3>
The smallest number possible is 123569
We use the smallest digit first, then next smallest and so on.
I'm assuming no repeat digits are allowed.


If it's not clear why that works, then consider the set {12,21} and it's fairly clear that 12 is the smaller of the two values. 
We have 1 go first then 2 next.
Another example would be {123,132,213,231,312,321} showing that 123 is the smallest and 321 is the largest.



Anyways back to the problem at hand.
The largest number possible is 965321. We work the previous logic in reverse.


Difference = largest - smallest = 965321-123569 = <font color=red size=4>841752</font> is the final answer.
</font>