The magic number 1.

Number one wonders if we multiply a number by the number of digits as well.

The result is as follows.

      1111              or             111111

             x                                         x

      1111                               111111

1234321                    12345654321     Answer

The result is a sequential number. The largest number is equal to the number of No. 1.

From 1, 2, ..... add value to the one by one by one until a maximum number of digits after it is lining up to  

come down one by one and so on. And finally, 2, 1.