Perhaps you already know what the
numbers are (*). A short definition would be this one:
Giuga numbers n: p|(n/p-1) for every prime
divisor p of n.
Nowadays there are only eleven known
The smallest and the largest are 30 (3 prime
factors) & 554079914617070801288578559178 (8 prime factors)
Among the many very attractive question arising
around the Giuga numbers I will just select one of them:
Compute one more Giuga number
(In doing so, I will strongly recommend at least
to read the following
(*) This puzzle came after some
discussion about the Giuga numbers with my friend A. Rupinski.