Source: wikibot/carmichael-number
= Carmichael number
{wiki=Carmichael_number}
A Carmichael number is a composite number \\( n \\) that satisfies Fermat's little theorem for all integers \\( a \\) that are coprime to \\( n \\). Specifically, Fermat's little theorem states that if \\( p \\) is a prime number, then for any integer \\( a \\) such that \\( a \\) is not divisible by \\( p \\), \\\[ a^\{p-1\} \\equiv 1 \\ (\\text\{mod\} \\ p).