28322...99999 (71323-digits)

This number is a prime.

Just showing those entries submitted by 'Broadhurst': (Click here to show all)

As of June 2005, (6973!+2)^3-3^2 was the largest known prime of the form a^b-c^d with integers {a,b,c,d} all greater than unity and either b or d greater than 2. [Broadhurst]