FACTOR(1)                                               FACTOR(1)

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

     SYNOPSIS
          factor [ number ]

          primes

     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 7.2e16) it will factor the number and
          print its prime factors; each one is printed the proper num-
          ber 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 sqrt(n) and occurs
          when n is prime or the square of a prime.  It takes 1 minute
          to factor a prime near 1014 on a PDP11.

          When primes is invoked, it waits for a number to be typed
          in.  If you type in a positive number less than 256 it will
          print all primes greater than or equal to this number.

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