# factor(C)

**factor --
factor a number
**

## Syntax

**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 2^46 (about
7.2×10^13) 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.

The time it takes to factor a number, *n*,
is proportional to *n*.
It usually takes longer to factor a prime
or the square of a prime, than to factor other numbers.

## Diagnostics

**factor** returns an error message if the supplied
input value is greater than 2^46 or is not an
integer number.

*
© 2003 Caldera International, Inc. All rights reserved.
*

SCO OpenServer Release 5.0.7 -- 11 February 2003