66263...79799 (30-digits)

This number is a prime.

                                            6626378631 2646216567 6291379799

Just showing those entries submitted by 'Rivera': (Click here to show all)

The largest prime in the base of a pyramid and sequence of primes that starts with "3" and obtains new primes in a procedure of preprending or appending one digit at a time on an appropriate side. [Rivera]