12815137

This number is a prime.

+ If you replace each digit of 12815137 with the digit's square, you obtain a new prime and up to six primes doing this recursively: 12815137 -> 14641251949 -> 116361614251811681 -> 11369361361164251641136641 -> 11936819361936113616425136161193636161 -> 1181936641819361819361193613616425193613611819369361361. [Rivera]

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