43143...00193 (38-digits)

This number is a prime.

                                   43143988 3273989572 7934241975 0374600193

The smallest Leyland prime (i.e., of the form x^y + y^x, where x and y are natural numbers, 1 less than x less than or equal to y) with x and y both composite numbers (x=15, y=32). [Beedassy]