FACTOR(VI) − PWB/UNIX 1/15/73
NAME
factor − discover prime factors of a number
SYNOPSIS
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 256 (about 7.2×1016) 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. Maximum time to factor is proportional to √n
‾ and occurs when n is prime or the square of a prime. It takes 1 minute to factor a prime near 1013.
DIAGNOSTICS
‘Ouch.’ for input out of range or for garbage input.
BUGS