Factorizer is a Windows program to find prime numbers, pairs of primes, and factors of numbers less than 2,147,483,647. It can be used (1) to get the prime decomposition of all numbers in a range of numbers, (2) to get all factors of a single number or all factors of all numbers in a range, (3) to find only the prime numbers in a range of numbers, (4) to find pairs of prime numbers in a certain range, (5) to count (without displaying) the prime numbers in a range of numbers, (6) to find Fermat and Mersenne primes < 2,147,483,647 and (7) to find the Palmen color of a number or the colors of a range of numbers.