R function to convert a number to text

I got bored after the millions, but this should handle the smaller 
numbers, and you can always extend it.

digits2text<-function(x,mult="") {
  units<-c("one","two","three","four","five",
   "six","seven","eight","nine")
  teens<-c("ten","eleven","twelve","thirteen","fourteen",
   "fifteen","sixteen","seventeen","eighteen","nineteen")
  tens<-c("ten","twenty","thirty","forty","fifty",
   "sixty","seventy","eighty","ninety")
  digits<-rev(as.numeric(strsplit(as.character(x),"")[[1]]))
  digilen<-length(digits)
  if(digilen == 2 && digits[2] == 1) return(teens[digits[1]+1])
  digitext<-units[digits[1]]
  if(digilen > 1) digitext<-c(digitext,tens[digits[2]])
  if(digilen > 2) digitext<-c(digitext,"hundred",units[digits[3]])
  if(digilen > 3) digitext<-
   c(digitext,digits2text(floor(x/1000),"thousand"))
  if(digilen > 6) digitext<-
   c(digitext,digits2text(floor(x/1000000),"million"))
  return(paste(c(rev(digitext),mult),sep="",collapse=" "))
}

digits2text(10^6 + 10)