21111...11113 (25-digits)

This number is a prime.

                                                 21111 1111111111 1111111113

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

+ Inserting twenty three 1's between the digits of the prime 23 we find another prime whose the product and the sum of digits are consecutive perfect numbers. [Loungrides]

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