13579...89819 (87-digits)

This number is a prime.

                                                          1357911 3151719112
3252729213 3353739314 3454749415 3555759516 3656769617 3757779718 3858789819

The largest prime less than a googol obtained by concatenating the digit reversal of first n odd numbers, (case n=45). [Bajpai]