26666...66667 (43-digits)

This number is a prime.

                             266 6666666666 6366666666 6666656666 6666666667

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The largest prime p less than a googol formed by inserting thirteen 6's in between the digits of the smallest distinct-digit prime-digit prime, containing all of the prime digits, i.e., 2357. Curiously, sod(p)=251 is also prime. [Bajpai]