10968
There are 5 different digits those could be read on reversing them, they are 0,1,6,8&9.
Where 0,1&8 can be read same after reversing, while 6&9 are read as 9&6 after reversing.
Now taking the assumption of no. 10968, add the diff no. 78633 which results to 89601 and on reversing the same it reads to be 10968.
Thus, the no. is 10968