88640...69401 (54-digits)

This number is a prime.

                 8864 0741000036 1345663448 5355402586 2249017914 2922169401

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

The smallest prime factor of W(M(127)), where M(n) is the Mersenne number 2^n-1 and W(n) is a Wagstaff number (2^n+1)/3. This proves that the Catalan-Mersenne conjecture and the New Mersenne conjecture cannot be both true, i.e. at least one of them is false. [Xayah]