calculates the prime numbers 1..N, tells you if N is prime etc. Prints tables of primes. Computes the prime just below or above N. calculates the prime numbers 1..N, tells you if N is prime etc. It is useful in computing optimal Hashtable sizes. Java source included.

Finds the prime factors of positive integers, solves triangles and circles problems, manipulates complex numbers, does base conversions. Results can be saved or printed. Includes a help file with instructions, example and methodology.

Factorizer may 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 and (6) to find Fermat and Mersenne primes less than 2,147,483,647.

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.