Mersenne Prime Research code

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;

namespace PrimeShits
{
    public partial class MainForm : Form
    {
        int primesNo = 100;

        public MainForm()
        {
            InitializeComponent();
        }

        private void numericUpDown1_ValueChanged(object sender, EventArgs e)
        {
            primesNo = (int)numericUpDown1.Value;
        }
        private void button1_Click(object sender, EventArgs e)
        {
            int[] primes = FindPrimes(primesNo);
            string[] results = new string[primesNo];
            string[] periods = new string[primesNo];
            DividePrimes(results, periods, ref primes);
            string[] fileData = new string[primesNo];
            string lastPrimeString = primes[primesNo - 1].ToString();
            char[] lastPrimeLength = lastPrimeString.ToCharArray();
            for (int i = 0; i < primesNo; i++)
            {
                string iString = primes[i].ToString();
                char[] iLength = iString.ToCharArray();
                fileData[i] += "1 / ";
                for (int j = 1; j < lastPrimeLength.Length - iLength.Length + 1; j++)
                    fileData[i] += "0";
                fileData[i] += primes[i].ToString() + ": Period grade: ";
                fileData[i] += periods[i].ToString();
            }
            File.WriteAllLines("C:/users/user/Desktop/primes.txt", fileData);
        }
        void DividePrimes(string[] results, string[] periods, ref int[] primes)
        {
            for (int i = 0; i < primesNo; i++)
            {
                bool period = false;
                int remainder = 10;
                string result = "0.";
                int times = 0;
                while (period == false)
                {
                    while (remainder >= primes[i])
                    {
                        remainder -= primes[i];
                        times++;
                    }
                    result += times.ToString();
                    times = 0;
                    remainder *= 10;
                    if (remainder == 10)
                        period = true;
                    if (remainder == 0)
                        break;
                }
                results[i] = result;
                char[] resultChar = result.ToCharArray();
                int periodLength = resultChar.Length - 2;
                periods[i] = periodLength.ToString();
            }
        }
        int[] FindPrimes(int totalPrimes)
        {
            int primesFound = 0;
            int no = 2;
            int[] primes = new int[totalPrimes];
            while (primesFound < totalPrimes)
            {
                bool isPrime = false;
                int totalNumbers = 0;
                for (int i = 1; i <= no; i++)
                {
                    int intResult = no / i;
                    double doubleResult = (double)no / (double)i;
                    if ((double)intResult == doubleResult)
                        totalNumbers++;
                    if (totalNumbers > 2)
                        break;
                }
                if (totalNumbers == 2)
                    isPrime = true;
                if (isPrime == true)
                {
                    primes[primesFound] = no;
                    primesFound++;
                }
                totalNumbers = 0;
                isPrime = false;
                no++;
            }
            return primes;
        }
    }
}