Sunday Times Teaser 2603 – Pandigital Square
by Des MacHale
Published: 12 August 2012 (link)
I call my telephone number “pandigital”, in the sense that it is a nine-figure number using each of the digits 1 to 9. Amazingly, it is a perfect square. Furthermore, its square root is a five-figure number consisting of five consecutive digits in some order.
It might interest you to know (although you do not need to) that my neighbour’s telephone number is also a nine-figure pandigital perfect square, but his is at least double mine.
With a little logic and not many calculations you should be able to work out my telephone number.
What is it?