Task: Text Categorization
Input (English): These entities can be found by using the Sieve of Eratosthenes (AIR-uh-TOSS-the-neez). According to Goldbach's conjecture, every integer greater than two can be expressed as a sum of two of them. Every positive integer can be expressed as a factorization of these numbers. For 10 points, identify these natural numbers whose only divisors are themselves and one.
Output (English): Science