Question

How many six digits perfect square number is there in a number system.

Answer 1

It has a factor of 11, so xyz must be divisible by 11. a must be 1, 4, 5, 6 or 9. All integer squares end in one of these digits or 0, and if a = 0, abccba is not a six digit number. If a is 9, then xyz must be between 949 and 999 (948^2 starts with an 8 and 1,000^2 is a seven digit number).