For security purposes I regularly change my six-digit passcode for internet banking. I always choose a code that is made up of three different two-digit square numbers (i. e. square numbers
between 10 and 99), with the sixth digit the same as the first digit.

-Which two digits never appear in any of my passcodes?

-How many different passcodes can I use?

The sum of the six digits of my current passcode is also a square number.

-What is my current passcode?