72727...72727 (99-digits)

This number is a prime.

                                             727272727 2727272727 2727272727
2727272727 2727272727 2727272727 2727272727 2727272727 2727272727 2727272727

7+720*(100^49-1)/99 is a 99-digit wondrous undulating prime. [Tobias]