33213

This number is a composite.

+ The smallest semiprime k such that replacing each digit d in decimal expansion of k with d^2 yields a new semiprime when done recursively six times, i.e., 33213-> 99419 (semiprime); 99419-> 818116181(semiprime); 818116181-> 6416411361641(semiprime); 6416411361641-> 36161361611936136161 (semiprime); 36161361611936136161-> 9361361936136118193619361361 (semiprime); 9361361936136118193619361361-> 8193619361819361936116418193618193619361 (semiprime). [Bajpai]

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