Answer:
81 x 10^6
Step-by-step explanation:
x0000000
11111111x
22222222
33333333
....................
88888888
99999999
---------------------
The first digit and 8th digit column has only 9 numbers and the rest 6 column have 10 possible numbers
9 x 9 x 10^6 = 81 x 10^6
