Carmichael numbers exhibit the property that for any base \( a \) coprime to the number, \( a^{n-1} \equiv 1 \mod n \) holds true, according to Fermat's Little Theorem. The discussion clarifies that for the Carmichael number 561, this property applies to all bases except its prime factors, which are 3, 11, and 17. The confusion arises from the distinction between the base of the exponent and the base of notation. Ultimately, Carmichael numbers should return 1 for bases that are coprime to them, reinforcing their unique mathematical characteristics. Understanding this distinction is crucial for correctly applying Fermat's theorem to Carmichael numbers.