Tallord C#7

using System;
using System.Collections.Generic;
using System.Linq;

namespace Numerals
{
    public class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(Numeral(1234567));
            Console.Read();
        }


        private static Dictionary<int, string> BasicNumerals = new Dictionary<int, string>
        {
            [0] = "",
            [1] = "en",
            [2] = "to",
            [3] = "tre",
            [4] = "fire",
            [5] = "fem",
            [6] = "seks",
            [7] = "syv",
            [8] = "åtte",
            [9] = "ni",
            [10] = "ti",
            [11] = "elleve",
            [12] = "tolv",
            [13] = "tretten",
            [14] = "fjorten",
            [15] = "femten",
            [16] = "seksten",
            [17] = "sytten",
            [18] = "atten",
            [19] = "nitten",
            [20] = "tjue",
            [30] = "tretti",
            [40] = "førti",
            [50] = "femti",
            [60] = "seksti",
            [70] = "sytti",
            [80] = "åtti",
            [90] = "nitti",
        };
        private static Dictionary<int, string> LogNumerals = new Dictionary<int, string>()
        {
            [0] = "",
            [2] = "hundre",
            [3] = "tusen",
            [6] = "million",
            [9] = "milliard",
            [12] = "billion",
        };

        public static string Numeral(long n)
        {
            string numeral = "";
            if (n < 0)
            {
                numeral = "minus ";
                n = -n;
            }

            Queue<string> output = new Queue<string>();
            Stack<NumeralUnit> units = new Stack<NumeralUnit>();

            int logarithm = 0;
            while (n > 0)
            {
                int digitValue = (int)(n % 10);
                units.Push(new NumeralUnit(digitValue, logarithm));

                n /= 10;
                logarithm++;
            }

            NumeralUnit? previousUnit = null;
            while (units.Any())
            {
                NumeralUnit unit = units.Pop();
                NumeralUnit? nextUnit = null;

                if (units.Any())
                    nextUnit = units.Peek();

                string unitNumeral = BasicNumerals[unit.DigitValue];

                if (unit.IsTens)
                {
                    unit.DigitValue *= 10;
                    unit.Log--;

                    units.Pop();
                    if (unit.DigitValue <= 10)
                    {
                        unit.DigitValue += (nextUnit?.DigitValue ?? 0);
                        unitNumeral = BasicNumerals[unit.DigitValue];
                    }
                    else
                        unitNumeral = BasicNumerals[unit.DigitValue] + BasicNumerals[nextUnit.Value.DigitValue];

                    if (units.Any())
                        nextUnit = units.Peek();
                }

                int tmpLog = -1;
                if (unit.IsHundred)
                    tmpLog = 2;
                else if (unit.IsThousands)
                    tmpLog = unit.Log;

                AppendSeparatingWord(output, previousUnit, unit, tmpLog);

                if (unit.DigitValue == 1 && (unit.IsHundred || unit.Log == 3))
                    unitNumeral = "ett";

                output.Enqueue(unitNumeral);

                if (tmpLog >= 0 && (unit.DigitValue != 0 || previousUnit?.IsHundred == true))
                {
                    unitNumeral = LogNumerals[tmpLog];
                    if (tmpLog > 3 && (unit.DigitValue > 1 || previousUnit?.IsHundred == true))
                        unitNumeral += "er";

                    output.Enqueue(unitNumeral);
                    previousUnit = unit;
                }

                if (unit.DigitValue != 0)
                    previousUnit = unit;
            }

            while (output.Any())
            {
                string token = output.Dequeue();
                if (token == ",")
                    numeral = numeral.Substring(0, numeral.Length - 1);
                numeral += token;

                if (token != "")
                    numeral += " ";
            }

            numeral = numeral.TrimEnd(' ');
            return numeral == "" ? "null" : numeral;
        }

        private static void AppendSeparatingWord(Queue<string> output, NumeralUnit? previousUnit, NumeralUnit unit, int tmpLog)
        {
            if (tmpLog >= 0 && unit.DigitValue != 0 && previousUnit.HasValue
                && (previousUnit?.IsHundred == false))
                output.Enqueue(",");
            else if (unit.DigitValue != 0 && unit.IsSmall && output.Any())
                output.Enqueue("og");
        }

        public struct NumeralUnit
        {
            public int DigitValue;
            public int Log;

            public NumeralUnit(int value, int log)
            {
                this.DigitValue = value;
                this.Log = log;
            }

            public bool IsTens => Log % 3 == 1;
            public bool IsHundred => Log % 3 == 2;
            public bool IsThousands => Log % 3 == 0 && Log > 0;

            public bool IsSmall => Log % 3 <= 1;
        }
    }
}