Determining a number is or is not a prime belongs to qualitative analysis. We canuse Sieve of Eratosthenes to determine that a number is or is not a prime. Sieve ofEratosthenes is a completely deterministic method for determining primes.In the positive integer sequence 1 → M, we use Sieve of Eratosthenes to graduallyremove multiples( including p′ itself) of all p′: first we obtain the G2 by eliminating themultiples of 2, next, obtain the intersection of G2 and G3 by eliminating the multiples of3 in G2, and then obtain the intersection of G2 , G3 and G5 by eliminating the multiplesof 5 in the intersection of G2 and G3, this continues, until obtain the intersection of Gp′from 2 to k′. The intersection of Gp′ of all p′ is equal to P∗.If we don’t consider time complexity, by Sieve of Eratosthenes, we can deterministicallyobtain all primes which are not greater than any given M.