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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