12508...40031 (19893-digits)
This number is a prime.
Just showing those entries submitted by 'Earls': (Click here to show all)
17763*2^66066-1 is prime. Note that 66066 is a palindromic triangular number, and that 1^2+7^2+7^2+6^2+3^2 = 6^2+6^2+0^2+6^2+6^2 = 144 = 12^2. [Earls]
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