To find the product of the number is discussed here.
We take the number formed by continuous writing of the digits from 1 to 9
except 8. The number is multiplied by the product of any one of the
digits and 9. The multiplied product is the number formed by writing the
same digit 9 times.
The result may be seen by multiplying 12345679 and 5 x 9, 8 x 9 ……..etc.