1000000008000000001

This number is a prime.

                                                        100000000 8000000001

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

The concatenation of (1, n 0s, n, n 0s, & 1), is the largest prime less than a googol of this type (n = 8). Note that this prime also palindrome and tetradic. [Marcel]