factor(C) 19 June 1992 factor(C) Name factor - factor a number Syntax factor [ number ] Description When factor is invoked without an argument, it waits for a number to be typed in. If you type in a positive number less than 2^46 (about 7.2e13) it will factor the number and print its prime factors; each one is printed the proper number of times. Then it waits for another number. It exits if it encounters a zero or any non-numeric character. If factor is invoked with an argument, it factors the number as above and then exits. The time it takes to factor a number, n, is proportional to sqrt(n). It usually takes longer to factor a prime or the square of a prime, than to factor other numbers. Diagnostics factor returns an error message if the supplied input value is greater than 2^46 or is not an integer number.