20000...02293 (64-digits)

This number is a prime.

      2000 0000000000 0000000000 0002000000 0000000000 0000000200 0000002293

Alphabetically, the last prime in English: "two vigintillion two undecillion two trillion two thousand two hundred ninety-three", via Knuth and Miller's Fall 1980 CS 204 class at Stanford. The seminar was in the USA so American English was used (101 = one hundred one, not one hundred and one; 1000000000 = one billion, not 1000000000000). [Rivera]