35711...11753 (231-digits)

This number is a prime.

                                                     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 obtained by concatenation of the consecutive odd primes from 3 up to 227 and then back down to 3 again. [Patterson]