7777
This number is a composite.
Just showing those entries submitted by 'Firoozbakht': (Click here to show all)
7777 = 6^5 + 1 is probably the only repdigit number of the
form (p+1)^p+1 where p is prime. Also, it is probably the
only multidigit repdigit number of the form (n+1)^n+1. [Firoozbakht]
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