I am searching the smallest squarefree number $n$ with $gnu(n)=79$. $n$ must have more then $3$ prime factors because $p+2\ne 79$ and $p+4\ne 79$ for every prime $p$.
The maximum possible number of $gnu(pqrs)$, where $p<q<r<s$ are primes, is $p^2+pq+3p+2q+8\ne 79$ for all primes $p,q$ with $p<q$.
But there might be a squarefree number $n$ with $4$ prime factors and $gnu(n)=79$.
What is the smallest squarefree number $n$ with $gnu(n)=79$ ?