This number is a prime.

Just showing those entries submitted by 'Gaydos': (Click here to show all)

+ The 65th emirp (1399) has a Collatz trajectory length of 65. [Gaydos]

+ The smallest prime number whose prime index (222) and sum of digits (22) together use only one digit. The next two such primes are 867746501 (44444444 and 44) and 1097774749 (55555555 and 55). [Gaydos]

(There is one curio for this number that has not yet been approved by an editor.)

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