FACTOR(1) FACTOR(1) NAME factor, lfactor, qfactor, primes - factor a number, generate large primes SYNOPSIS factor [ number ] lfactor qfactor primes [ start [ finish ] ] DESCRIPTION Factor prints number and its prime factors, each repated the proper number of times. The number must be positive and less than 2**56 (about 7.2e16) 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 time to factor is proportional to sqrt(n) and occurs when n is prime or the square of a prime. Lfactor reads one number from the standard input and factors it. Worst-case running time is proportional to n**(1/5); it beats factor for hard 12-digit problems and is workable to around n=10**30. Qfactor reads one number from the standard input and factors it. It is almost always better than lfactor , and will factor numbers up to about 40 digits. 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. DIAGNOSTICS `Ouch.' for input out of range or for garbage input. BUGS Lfactor makes mysterious progress reports on its arcane inner workings. Qfactor does too.