Carmichael Condition
A number n satisfies the Carmichael condition iff (p-1)|(n/p-1) for all prime divisors p of n. This is equivalent to the condition (p-1)|(n-1) for all prime divisors p of n.
See also
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References
Borwein, D.; Borwein, J. M.; Borwein, P. B.; and Girgensohn, R. "Giuga's Conjecture on Primality." Amer. Math. Monthly 103, 40-50, 1996.Referenced on Wolfram|Alpha
Carmichael ConditionCite this as:
Weisstein, Eric W. "Carmichael Condition." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/CarmichaelCondition.html