73
This number is a prime.
Just showing those entries submitted by 'Galliani': (Click here to show all)
73 divides both 17!-1 and 71!-1. [Galliani]
73 is the concatenation (in decreasing order) of the first two Mersenne primes, 3 and 7. [Galliani]
(There are 2 curios for this number that have not yet been approved by an editor.)
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