### factor (1)

#### NAME

factor, primes - factor a number, generate large primes#### SYNOPSIS

**factor**[

*number*]

**primes**
[
*start*
[
*finish*
]
]

#### DESCRIPTION

*Factor*prints

*number*and its prime factors, each repeated the proper number of times. The number must be positive and less than 2**54 (about 1.8e16)

If no
*number *
is given,
*factor*
reads a stream of numbers from the standard input and factors them.
It exits on any input not a positive integer.
Maximum running time is proportional to
sqrt(n).

*Primes*
prints the prime numbers ranging from
*start*
to
*finish*,
where
*start*
and
*finish*
are positive numbers less than
2**56.
If
*finish*
is missing,
*primes*
prints without end;
if
*start*
is missing, it reads the starting number from the
standard input.

#### SOURCE

**/src/cmd/factor.c**

**/src/cmd/primes.c**