11110...01111 (73-digits)

This number is a prime.

                                                                         111
1011111001 1111000800 0110888801 1081801108 8880110008 0001111100 1111101111

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

             1
            1 1
           1 0 1
    1 1 1 1 0 0 1 1 1 1
     1 0 0 0 8 0 0 0 1
      1 0 8 8 8 8 0 1
       1 0 8 1 8 0 1
      1 0 8 8 8 8 0 1
     1 0 0 0 8 0 0 0 1
    1 1 1 1 0 0 1 1 1 1
           1 0 1
            1 1
             1