by Graham Smithers
I have six identical dice, each with digits in place of the corresponding number of dots on a standard six sided die. I arranged these in a three layered triangular stack with three dice on the bottom, two in the middle and one on the top. All the visible (or partly visible) top faces could be seen to be different.
The one, two and three digit numbers seen horizontally when viewed from the front were primes and from the back were squares. Working from top to bottom, the numbers seen from the left and right were a perfect square and a prime respectively.
What was the latter prime?