11111...99999 (60-digits)

This number is a prime.

           1111111111 1111111222 2333333333 3344455566 7777777777 7889999999

+ The ordered digits from the concatenation of the first 31 primes is prime. Here leading zeros can be ignored. It is the largest known prime formed in this way, as of 2018. [Antonious]

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