0.2357111317192329313...

This number is neither prime nor composite.

                                                                       0.235
7111317192 3293137414 3475359616 7717379838 9971011031 0710911312 7131137139

In 1946 Copeland and Erdös proved that the decimal number obtained by adjoining all of the primes was normal. That is, any pattern of k-digits must occur 1/10^k of the time in the decimal expansion. (It is not normal in every base.) [Caldwell]