439

This number is a prime.

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Take the sum of emirp 439 and its reversal: 439 + 934 = 1373. If we split 1373 in half and factor, we get 13*73 = 949 = 227+722 (a prime and its reversal). Note that 439+722 = 1161 = 934+227 uses each of the above primes and their reversals. [Bergot]