Here is a technical definition of "cyclotomic polynomial", if you can understand it!!. Good luck.
"A polynomial given by Φ_n(x) = product_(k = 1)^n'(x - ζ_k), where ζ_k are the roots of unity in C given by ζ_k congruent e^(2πik/n) and k runs over integers relatively prime to n. The prime may be dropped if the product is instead taken over primitive roots of unity, so that Φ_n(x) = product_k = 1 primitive ζ_k^n(x - ζ_k)."
