9 just after 8

7 just before 8 

The product of the succeeding number and the preceding number of 8 is : (8 - 1)(8 + 1) = 7.9 = 63

Just after 8 is: 9

Just before 8 is: 7

So the product of just after and just before 8 is: \(9+7=16\).

So the answer is: \(16\)