This number is a prime.

+ The largest emirp less than a googol that can be represented as the sum of a repdigit number consisting of 6’s and all of its truncations plus 1, i.e., 666666+66666+6666+666+66+6+1, so that deleting the largest repdigit, 666666, the remaining sum, i.e., 66666+6666+666+66+6+1 = 74071, is also emirp. [Loungrides]

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