Prime Number Spiral 

The Prime Number Spiral (a.k.a. the Ulam Spiral) is formed by marking the prime numbers in a spiral arrangement of the natural numbers. This is software is for exploring the Prime Number Spiral.
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Factorizer 

A program to find prime numbers and pairs of primes, to decompose numbers into their prime constituents, to find all factors of any positive integer up to 2,147,483,645, and to plot Erdos-Kac and Palmen Color histograms.
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