First half of the chessboard

There are 232 − 1 = 4,294,967,295 grains on the first half of the chessboard., English Wikipedia
It is also the product of the known Fermat primes, and therefore the number of sides in the largest known odd-sided .
== Sources ==
Category:Numbers
Category:Chess
Category:Class 2
Category:Non-powers
Category:Numbers with 7 to 29 digits
Category:Odd numbers