This number is a prime.
1056208858880824379 is a prime that remains prime when you substitute all the digits x with 3, for x = 0 to 9, each substitution one at a time. E.g., if x = 0, then the new integer is 135623885888382437 (prime); for x = 1, the new integer is 3056208858880824379 (prime), and so on. Found by Giovanni Resta. [Rivera]