54572...17991 (30-digits)

This number is a prime.

                                            5457218978 9429924839 3823917991

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 "2" and obtains new primes in a procedure of preprending or appending one digit at a time on an appropriate side. [Rivera]