FACTOR(6) | Games Manual | FACTOR(6)

# NAME

`factor`, `primes` — factor a number, generate primes

# SYNOPSIS

`factor` | [number ...]

`primes` | [start [stop]]

# DESCRIPTION

The `factor` utility will factor 64-bit positive integers. When a number is factored, it is printed, followed by a ‘:’, and the list of its prime factors in ascending order, on a single line. Every prime factor is printed as often as it divides the number.

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. White-space and empty lines are ignored. Numbers may be preceded by a single +. After a number is read, it is factored. Input lines must not be longer than 99 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 input line must not be longer than 99 characters.

# BUGS

`factor` cannot handle the “10 most wanted” factor list; `primes` won't get you a world record.

December 30, 2015 | Debian