5555

This number is a composite.

+ The sum of the 9th + 18th + 27th + ..... + 135th prime. [Bopardikar]

+ 5555n + 162 is prime for n = 0 to 7. [Blanchette]

+ The decimal part of 55551/3 starts with the reversal of its integer part (which happens to be an emirp), i.e., 17.71.... [De Geest]

+ The 2nd repdigit number consisting of 5’s whose the product with all its truncations plus 2 is prime, i.e., 5555*555*55*5+2=847831877. The previous such prime is 55*5+2=277 and the next is 55555555*5555555*…*5+2. [Loungrides]

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