How can I convert an integer into its verbal representation?

Question

Is there a library or a class/function that I can use to convert an integer to it\'s verbal representation?

Example input:

4,567,788`

Answer 1

Though this is kind of old question, I have implemented this functionality with more detailed approach

public static class NumberToWord
    {
        private static readonly Dictionary MyDictionary = new Dictionary();

        static NumberToWord()
        {
            MyDictionary.Add(1000000000000000, "quadrillion");
            MyDictionary.Add(1000000000000, "trillion");
            MyDictionary.Add(1000000000, "billion");
            MyDictionary.Add(1000000, "million");
            MyDictionary.Add(1000, "thousand");
            MyDictionary.Add(100, "hundread");
            MyDictionary.Add(90, "ninety");
            MyDictionary.Add(80, "eighty");
            MyDictionary.Add(70, "seventy");
            MyDictionary.Add(60, "sixty");
            MyDictionary.Add(50, "fifty");
            MyDictionary.Add(40, "fourty");
            MyDictionary.Add(30, "thirty");
            MyDictionary.Add(20, "twenty");
            MyDictionary.Add(19, "nineteen");
            MyDictionary.Add(18, "eighteen");
            MyDictionary.Add(17, "seventeen");
            MyDictionary.Add(16, "sixteen");
            MyDictionary.Add(15, "fifteen");
            MyDictionary.Add(14, "fourteen");
            MyDictionary.Add(13, "thirteen");
            MyDictionary.Add(12, "twelve");
            MyDictionary.Add(11, "eleven");
            MyDictionary.Add(10, "ten");
            MyDictionary.Add(9, "nine");
            MyDictionary.Add(8, "eight");
            MyDictionary.Add(7, "seven");
            MyDictionary.Add(6, "six");
            MyDictionary.Add(5, "five");
            MyDictionary.Add(4, "four");
            MyDictionary.Add(3, "three");
            MyDictionary.Add(2, "two");
            MyDictionary.Add(1, "one");
            MyDictionary.Add(0, "zero");
        }

        /// 

        /// To the verbal.
        /// 
        /// The value.
        /// 
        public static string ToVerbal(this int value)
        {
            return ToVerbal((long) value);
        }

        /// 

        /// To the verbal.
        /// 
        /// The value.
        /// 
        public static string ToVerbal(this long value)
        {
            if (value == 0) return MyDictionary[value];

            if (value < 0)
                return $" negative {ToVerbal(Math.Abs(value))}";

            var builder = new StringBuilder();

            for (var i = 1000000000000000; i >= 1000; i = i/1000)
                value = ConstructWord(value, builder, i);

            value = ConstructWord(value, builder, 100);

            for (var i = 90; i >= 20; i = i - 10)
                value = ConstructWordForTwoDigit(value, builder, i);

            if (MyDictionary.ContainsKey(value))
                builder.AppendFormat("{0}" + MyDictionary[value], builder.Length > 0 
                    ? " " 
                    : string.Empty);

            return builder.ToString();
        }

        private static long ConstructWord(long value, StringBuilder builder, long key)
        {
            if (value >= key)
            {
                var unit = (int) (value/key);
                value -= unit*key;
                builder.AppendFormat(" {0} {1} " + MyDictionary[key], builder.Length > 0
                    ? ", "
                    : string.Empty, ToVerbal(unit));
            }
            return value;
        }
        private static long ConstructWordForTwoDigit(long value, StringBuilder builder, long key)
        {
            if (value >= key)
            {
                value -= key;
                builder.AppendFormat(" {0} " + MyDictionary[key], builder.Length > 0
                    ? " "
                    : string.Empty);
            }
            return value;
        } 
    }

FYI: i have user string interpolation which is only available in 4.6.1