Factors of an integer: Difference between revisions

Instead of displaying 1 and the number itself as factors, prime numbers are explicitly reported as such. To reduce the number of test divisions, only odd divisors are tested if an initial check shows the number to be factored is not even. The upper limit of divisors is set at N/2 or N/3, depending on whether N is even or odd, and is continuously reduced to N divided by the next potential divisor until the first factor is found. For a prime number the resulting limit so reduced will be the square root of N, which avoids the necessity of explicitly calculating that value. (ALGOL-M does not have a built-in square root function.)