1409

This number is a prime.

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

+ The smallest emirp such that the emirp pair are PIPs [Prime-Indexed Primes]. E.g., 1409 is the 223rd prime and 9041 is the 1123rd prime. Both 223 and 1123 are prime. Emirpips? [Green]

+ Each of the states North Dakota, Rhode Island, and Wyoming have just one area code for the state and they are 701, 401, 307, respectively, and each is a prime. Curiously, the sum of the three codes is an emirp (which happens to be a twin prime). [Green]

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