The Prime Number Spiral (a.k.a. the Ulam Spiral) is constructed as follows: Consider a rectangular grid. We start with the central point and arrange the positive integers in a spiral fashion (anticlockwise). The prime numbers are then marked. There is a tendency for the prime numbers to occur on diagonal lines, however far out into the spiral one goes. This is software is for exploring the Prime Number Spiral. It also (a) allows coloring of the prime numbers in various ways, (b) displays a random arrangement to compare with the primes and (c) shows how square and triangular numbers are located on the spiral.

Prime Number Spiral 7.42 has been tested on 2006-09-05 and received a complete evaluation by the Soft32Download experts and due to the great results it has been awarded with the "Clean & Safe" award, meaning that this product is 100% clean of adware/spyware/trojans/viruses and it is safe to install.