English words for numbers

word.rb

def word(n)
  divisors = {
    :vigintillion      => 10**63,   :novemdecillion  => 10**60,
    :octodecillion     => 10**57,   :septendecillion => 10**54,
    :sexdecillion      => 10**51,   :quindecillion   => 10**48,
    :quattuordecillion => 10**45,   :tredecillion    => 10**42,
    :duodecillion      => 10**39,   :undecillion     => 10**36,
    :decillion         => 10**33,   :nonillion       => 10**30,
    :octillion         => 10**27,   :septillion      => 10**24,
    :sextillion        => 10**21,   :quintillion     => 10**18,
    :quadrillion       => 10**15,   :trillion        => 10**12,
    :billion           => 10**9,    :million         => 10**6,
    :thousand          => 10**3,    :hundred         => 100
  }
  subtrahends = {
    :ninety            => 90,       :eighty          => 80,
    :seventy           => 70,       :sixty           => 60,
    :fifty             => 50,       :forty           => 40,
    :thirty            => 30,       :twenty          => 20,
    :nineteen          => 19,       :eighteen        => 18,
    :seventeen         => 17,       :sixteen         => 16,
    :fifteen           => 15,       :fourteen        => 14,
    :thirteen          => 13,       :twelve          => 12,
    :eleven            => 11,       :ten             => 10,
    :nine              => 9,        :eight           => 8,
    :seven             => 7,        :six             => 6,
    :five              => 5,        :four            => 4,
    :three             => 3,        :two             => 2,
    :one               => 1
  }
  return "negative " + word(-n) if n < 0
  return '' if n == 0
  
  divisors.each do |name, value| 
    if n >= value
      return word(n/value) + "#{name} " + word(n % value)
    end
  end
  subtrahends.each do |name, value|
    if n >= value
      return "#{name} " + word(n - value)
    end
  end
end