**NAME**
factor, primes - factor a number, generate primes
**SYNOPSIS**
**factor** [ number ] ...
**primes** [ start [ stop ]]
**DESCRIPTION**
The *factor* utility will factor integers between -2147483648
and 2147483647 inclusive. When a number is factored, it is
printed, followed by a ``:'', and the list of factors on a
single line. Factors are listed in ascending order, and are
preceded by a space. If a factor divides a value more than
once, it will be printed more than once.
When *factor* is invoked with one or more arguments, each
argument will be factored.
When *factor* is invoked with no arguments, *factor* reads
numbers, one per line, from standard input, until end of
file or error. Leading white-space and empty lines are
ignored. Numbers may be preceded by a single - or +.
Numbers are terminated by a non-digit character (such as a
newline). After a number is read, it is factored. Input
lines must not be longer than 255 characters.
The *primes* utility prints primes in ascending order, one per
line, starting at or above **start** and continuing until, but
not including **stop.** The **start** value must be at least 0 and
not greater than **stop.** The **stop** value must not be greater
than 4294967295. The default value of **stop** is 4294967295.
When the *primes* utility is invoked with no arguments, **start**
is read from standard input. **Stop** is taken to be
4294967295. The **start** value may be preceded by a single +.
The **start** value is terminated by a non-digit character (such
as a newline). The input line must not be longer than 255
characters.
**DIAGNOSTICS**
Out of range or invalid input results in `ouch' being
written to standard error.
**BUGS**
*Factor* cannot handle the ``10 most wanted'' factor list,
*primes* won't get you a world record.