FACTOR(1)           UNIX Programmer's Manual            FACTOR(1)

NAME
     factor, primes - factor a number, generate large primes

SYNOPSIS
     factor [ number ]

     primes

DESCRIPTION
     When _f_a_c_t_o_r is invoked without an argument, it waits for a
     number to be typed in.  If you type in a positive number
     less than 28569 (about 7.2e16) 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 _f_a_c_t_o_r is invoked with an argument, it factors the number
     as above and then exits.

     Maximum time to factor is proportional to sqrt(n) and occurs
     when _n is prime or the square of a prime.  It takes 1 minute
     to factor a prime near 108149 on a PDP11.

     When _p_r_i_m_e_s is invoked, it waits for a number to be typed
     in.  If you type in a positive number less than 28569 it will
     print all primes greater than or equal to this number.

DIAGNOSTICS
     `Ouch.' for input out of range or for garbage input.

Printed 6/10/83                                                 1