N is a number with the property that all its digits are even.
3N also has that property.
Example: N=208 and 3N=624.

How many possible values of N have 22 digits? (3N may have 22 or 23 digits.)

For reference: Evened N and 3N is a version of this problem where N is only a 3 digit number.

The # possible values of N having 22 digits is  325919783936.

Edited on July 30, 2023, 1:23 am

Posted by K Sengupta on 2023-07-30 01:22:59