Task: Text Categorization
Input (English): Implicants of this type are minimal in their number of literals when considering Boolean functions. Finite fields can only have orders of this type. Elements of this type in rings divide some element in an arbitrary factorization and they are equivalent to irreducible elements in a unique factorization domain. The fundamental theorem of arithmetic states that a number may be written as a unique product of numbers of this type. The Sieve of Eratosthenes was an early method for finding these numbers. For 10 points, identify this adjective that, when applied to the natural numbers, describes a number with exactly two divisors.
Output (English): Science