It's hard to post code here but I think this works.

// most code stolen from
// https://www.geeksforgeeks.org/segmented-sieve-print-primes-in-a-range/

#include <bits/stdc++.h>

#include "BigInt.hpp"  // https://faheel.github.io/BigInt/

using namespace std;
// fillPrime function fills primes from 2 to sqrt of high in chprime(vector) array
void fillPrimes(vector<int>& prime, int high)
{
    bool ck[high + 1];
    memset(ck, true, sizeof(ck));
    ck[1] = false;
    ck[0] = false;
    for (int i = 2; (i * i) <= high; i++) {
        if (ck[i] == true) {
            for (int j = i * i; j <= sqrt(high); j = j + i) {
                ck[j] = false;
            }
        }
    }
    for (int i = 2; i * i <= high; i++) {
        if (ck[i] == true) {
            prime.push_back(i);
        }
    }
}
// in segmented sieve we check for prime from range [low, high]
void segmentedSieve(int low, int high)
{
    if (low<2 and high>=2){
        low = 2;
    }//for handling corner case when low = 1 and we all know 1 is not prime no. 
    bool prime[high - low + 1];
  //here prime[0] indicates whether low is prime or not similarly prime[1] indicates whether low+1 is prime or not
    memset(prime, true, sizeof(prime));
 
    vector<int> chprime;
    fillPrimes(chprime, high);
    //chprimes has primes in range [2,sqrt(n)]
     // we take primes from 2 to sqrt[n] because the multiples of all primes below high are marked by these 
   // primes in range 2 to sqrt[n] for eg: for number 7 its multiples i.e 14 is marked by 2, 21 is marked by 3,
   // 28 is marked by 4, 35 is marked by 5, 42 is marked 6, so 49 will be first marked by 7 so all number before 49 
  // are marked by primes in range [2,sqrt(49)] 
    for (int i : chprime) {
        int lower = (low / i);
        //here lower means the first multiple of prime which is in range [low,high]
        //for eg: 3's first multiple in range [28,40] is 30          
        if (lower <= 1) {
            lower = i + i;
        }
        else if (low % i) {
            lower = (lower * i) + i;
        }
        else {
            lower = (lower * i);
        }
        for (int j = lower; j <= high; j = j + i) {
            prime[j - low] = false;
        }
    }
   

    BigInt numerator, denominator, remainder;

    // You'll need to set your terminal to 60 columns for this 
    // to look right. 
    numerator = 
    "111111111111111111111111111111111111111111111111111111111111" //line 01
    "111111111111111111111111111111111111111111111111111111111111" //line 02
    "111111111111111111111111111111111111111111111111111111111111" //line 03 
    "111111111111111111111111111111111111111111111111111111111111" //line 04
    "111111111111111111111111111111111111111111111111111111111111" //line 05
    "111111111111111111111111111111111111111111111111111111111111" //line 06 
    "111111111111188888888888111111111111111111888811111111111111" //line 07 
    "111111111111118888888888881111111111111188888111111111111111" //line 08 
    "111111111111111888811118888111111111118888811111111111111111" //line 09 
    "111111111111111118888111888811111111188881111111111111117111" //line 10 // originally ends 7111
    "111111111111111111888811188888111118888811111111111111111111" //line 11 
    "111111111111111111188888111888811888881111111111111111111111" //line 12 
    "111111111111111111111888811188888888111111111111111111111111" //line 13 
    "111111111111111111111188881118888811111111111111111111111111" //line 14 
    "111111111111111111111118888811188881111111111111111111111111" //line 15 
    "111111111111111111111111188881118888811111111111111111111111" //line 16 
    "111111111111111111111111188888811188881111111111111111111111" //line 17 
    "111111111111111111111118888888881118888111111111111111111111" //line 18 
    "111111111111111111111888881118888111888881111111111111111111" //line 19 
    "111111111111111111118888111111888881118888111111111111111111" //line 20 
    "111111111111111111888881111111118888111888811111111111111111" //line 21 
    "111111111111111188888111111111111888811118888111111111111111" //line 22 
    "111111111111118888811111111111111188888888888811111111111111" //line 23 
    "111111111111188881111111111111111111888888888881111111111111" //line 24 
    "111111111111111111111111111111111111111111111111111111111111" //line 25 
    "111111111111111111111111111111111111111111111111111111111111" //line 26 
    "111111111111111111111111111111111111111111111111111111111111" //line 27 
    "111111111111111111111111111111111111111111111111111111111111" //line 28 
    "111111111111111111111111111111111111111111111111111111111111" //line 29 
    "111111111111111111111111111111111111111111111111111111111111"; //line 30
	    

    int primecount=0;
    BigInt root;
    root = sqrt(numerator);
    cout << "A prime factor might be as large as sqrt(n) " << endl << root << endl;
    cout << "Looking for factors for " << endl << numerator << endl;
    for (int i = low; i <= high; i++) {
        if (prime[i - low] == true) {
	    primecount++;
	    denominator = i;
	    remainder = numerator%denominator;
	    if( remainder==0 )
            {
            	cout << endl << (i) << " * " <<endl<< numerator/denominator << "\n";
	    }
        }
    }
    cout << "Found " << primecount << " primes from "<< low << " to " << high << endl;
}
int main()
{
    // low should be greater than or equal to 2
    int low = 2;
    // low here is the lower limit
    int high = 1001000;
    // high here is the upper limit
      // in segmented sieve we calculate primes in range [low,high] 
   // here we initially we find primes in range [2,sqrt(high)] to mark all their multiples as not prime
   //then we mark all their(primes) multiples in range [low,high] as false
   // this is a modified sieve of eratosthenes , in standard sieve of  eratosthenes we find prime from 1 to n(given number)
   // in segmented sieve we only find primes in a given interval 
  cout<<"Primes in range "<<low<<" to "<< high<<" are\n";
    segmentedSieve(low, high);
}