    FACTOR(VI)                   1/15/73                   FACTOR(VI)

    NAME
         factor - discover prime factors of a number

    SYNOPSIS
         factor

    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 1013.

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

    BUGS

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