factor(1) — USER COMMANDS
NAME
factor − obtain the prime factors of a number
SYNOPSIS
factor [integer]
DESCRIPTION
When you use factor without an argument, it waits for you to give it an integer. After you give it a positive integer less than or equal to 1014, it factors the integer, prints its prime factors the proper number of times, and then waits for another integer. factor exits if it encounters a zero or any non-numeric character.
If you invoke factor with an argument, it factors the integer as described above, and then it exits.
The maximum time to factor an integer is proportional to √n
‾. factor will take this time when n is prime or the square of a prime.
DIAGNOSTICS
factor prints the error message, Ouch, for input out of range or for garbage input.
— User Environment Utilities