Quote:
Originally Posted by Glenio
70237298350549551468899 รก is congruent with 1 (mod 4) and no cofactor is also known; therefore, there may still be a chance that 2 ^ 702372983505495514688991 is prime. This is just an example that I am taking into account.

Is it 3 mod 4?
How many tons of coal are needed to LL test it?
What do you calculate the "chance" of being prime is?
Let me give you an example prime p=2^825899331 definitely has no small factors. So is 2^p1 prime? Anyone?