my_primeFactors <- function(num) {

    current <- num
    ret.vals <- vector()
    x <- 2
    while (x <= num - 1){
        while (current %% x == 0) {
            current <- current / x
            ret.vals <- c(ret.vals, x)
        }
        x <- x + 1
    }
    if (is.logical(ret.vals)) return(num) else return(ret.vals)
}

> my_primeFactors(12)
[1] 2 2 3

> primeFactors(n)
[1] 2 2 3

> as.numeric(factorize(12))
[1] 2 2 3

> # Rutina ad-hoc
> system.time({my_primeFactors(n)})
   user  system elapsed
  9.980   0.000  10.031
> # Paquete "numbers"
> system.time({primeFactors(n)})
   user  system elapsed
  0.004   0.000   0.001
> # Paquete "gmp"
> system.time({as.numeric(factorize(n))})
   user  system elapsed
      0       0       0

library(gmp)
getPrimeFactors = function(n){
    primeList=c()
    if(isprime(n)){
        primeList <- append(primeList, n)
        return (primeList)
    }
    currentPrime <- 2
    while(TRUE){
        # Check if input is divisible by the current primeList
        if(n %% currentPrime == 0){
            cat(sprintf("the number %f is divisible by %fn", n, currentPrime))
            n = n%/%currentPrime
            cat(sprintf("current prime :%fn", currentPrime))
            primeList = append(primeList,currentPrime)
            currentPrime = 2
            if(isprime(n)){
                primeList <- append(primeList, n)
                return (primeList)
            }
        }
        else{
            #cat(sprintf("the number %f is NOT divisible by %fn", n, currentPrime))
            #cat(sprintf("current prime before is: %fn", currentPrime))
            print(c("current prime before:", currentPrime))
            currentPrime = as.numeric(nextprime(currentPrime))
            #cat(sprintf("current prime after is: %fn", currentPrime))
            print(c("current prime after:", currentPrime))
        }
    }
}