Number-theoretic transforms of prescribed length
Reiner Manfred Creutzburg, Manfred Tasche · Mathematics of Computation · 1986
A new constructive method for finding all convenient moduli m for a number-theoretic transform with given length N and given primitive N th root of unity modulo m is presented. This method is based on the prime factorization of cyclotomic polynomials with integer-valued argument or on the primitive divisors of integers. Many known results can be obtained as simple corollaries.