Number Puzzles :: Discussion

While visiting a small town in the United States, I lost my overcoat on a bus. When I reported the matter to the bus company I was asked the number of the bus. Though I did not remember the exact number I did remember that the bus number bad a certain peculiarity about it. The number plate showed the bus number as a perfect square and also if the plate was turned upside down.? the number would still be a perfect square—of course, it was not?
I came to know from the bus company they had only five hundred buses numbered from 1 to S00.
From this I was able to deduce the bus number. Can you tell what was the other number?