Convert Number to String representation

Sometimes we come across where we want to convert number to text , so here is the recursion code for same

public static string NumberToText(int n)
{
if (n < 0)
return "Minus " + NumberToText(-n);
else if (n == 0)
return "";
else if (n <= 19)
return new string[] {"first", "second", "Third", "Fourth", "Fiveth", "Sixth", "Seventh", "Eighth",
"Nineth", "Tenth", "Eleventh", "Twelveth", "Thirteenth", "Fourteenth", "Fifteenth", "Sixteenth",
"Seventeenth", "Eighteenth", "Nineteenth"}[n - 1] + " ";
else if (n <= 99)
return new string[] {"Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy",
"Eighty", "Ninety"}[n / 10 - 2] + " " + NumberToText(n % 10);
else if (n <= 199)
return "One Hundred " + NumberToText(n % 100);
else if (n <= 999)
return NumberToText(n / 100) + "Hundreds " + NumberToText(n % 100);
else if (n <= 1999)
return "One Thousand " + NumberToText(n % 1000);
else if (n <= 999999)
return NumberToText(n / 1000) + "Thousands " + NumberToText(n % 1000);
else if (n <= 1999999)
return "One Million " + NumberToText(n % 1000000);
else if (n <= 999999999)
return NumberToText(n / 1000000) + "Millions " + NumberToText(n % 1000000);
else if (n <= 1999999999)
return "One Billion " + NumberToText(n % 1000000000);
else
return NumberToText(n / 1000000000) + "Billions " + NumberToText(n % 1000000000);
}