SYNOPSISfactor [ number ]
primes [ start [ finish ] ]
DESCRIPTIONFactor 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.