35711...11753 (231-digits)

This number is a probable-prime (likely to be a prime but we have not (re-)proven it on this site).

                                                     3 5711131719 2329313741
4347535961 6771737983 8997101103 1071091131 2713113713 9149151157 1631671731
7918119119 3197199211 2232272232 1119919719 3191181179 1731671631 5715114913
9137131127 1131091071 0310197898 3797371676 1595347434 1373129231 9171311753

+ A prime of the form abcdcba, where a,b,c,d, ... are odd primes (35711...223227223...11753). Can you find a larger one? [Sariyar]

Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell