12191...19121 (37-digits)

This number is a prime.

                                    1219113 0363711159 7579511173 6303119121

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

A prime with prime sum of digits that forms the bottom row in a Palindromic Prime Pyramid of Step Size Two which begins: 5, 97579, 159757951, .... [Patterson]