139717391739171397

This number is a prime.

                                                         13971739 1739171397

A carousel (or merry-go-round) prime, i.e., for each digit 1->3->7->9->1: 139717391739171397, 371939713971393719, 793171937193717931, 917393179317939173. Note that each of the four are emirps. Found by Giuliano Daddario, 2001. [Rivera]