30000...00003 (41-digits)

This number is a prime.

                               3 0000000000 0000000007 0000000000 0000000003

   A "Naughty" Palindromic Prime Pyramid

                   101
                  10301
                 1003001
                100030001
               10000500001
              1000008000001
             300000020000003
            10000000500000001
           1000000008000000001
          700000000030000000007
         10000000000300000000001
        7000000000005000000000007
       100000000000080000000000001
      10000000000000300000000000001
     3000000000000005000000000000003
    100000000000000030000000000000001
   10000000000000000800000000000000001
  7000000000000000003000000000000000007
 300000000000000000010000000000000000003
30000000000000000000700000000000000000003

                [Honaker]