Carmichael Condition

A number $n$ satisfies the Carmichael condition Iff $(p-1)\vert(n/p-1)$ for all Prime Divisors $p$ of $n$. This is equivalent to the condition $(p-1)\vert(n-1)$ for all Prime Divisors $p$ of $n$.

See also Carmichael Number

References

Borwein, D.; Borwein, J. M.; Borwein, P. B.; and Girgensohn, R. ``Giuga's Conjecture on Primality.'' Amer. Math. Monthly 103, 40-50, 1996.