Getting "Floating point exception: 8" (I'm using Visual Studio Code) - c++

Question

#include <iostream>
using namespace std;
int findPrime(unsigned long long int number);
bool isPrime(unsigned long long int number);
int main(){
const unsigned long long int bound = 600851475143;
cout << findPrime(bound) << endl;
}
int findPrime(unsigned long long int number){
int largestFactor = 0;
for(int i = 1; i <= sqrt(number); i++){
if(number % i == 0){
int possible = number/i;
if(isPrime(possible))
largestFactor = possible;
}
}
return largestFactor;
}
bool isPrime(unsigned long long int number){
for(int i = 0; i <= sqrt(number); i++){
if(number % i == 0){
return true;
}
}
return false;
}
The purpose of this code is to find the largest prime factor. I am getting Floating point exception: 8 when running it, it is in Visual Studio Code and I am running from terminal.

Answer 1

In the first iteration of this code
bool isPrime(unsigned long long int number){
for(int i = 0; i <= sqrt(number); i++){
if(number % i == 0){
return true;
}
}
return false;
}
Division by zero is done, but it is not allowed. The loop should start from 2, not 0, for primality checking.

Answer 2

#include <iostream>
#include <math.h>
using namespace std;
int findPrime(long long int number);
bool isPrime(long long int number);
int main(){
long long int bound = 600851475143;
cout << findPrime(bound) << endl;
}
int findPrime(long long int number){
long long int largestFactor = 0;
for(int i = 1; i*i <=number; i++){
if(number % i == 0){
long long int possible = number/i;
if(isPrime(possible)){
largestFactor = possible;
largestFactor = 1;
}
}
}
return number;
if(largestFactor == 0){
return number;
}
return largestFactor;
}
bool isPrime(long long int number){
for(int i = 2; i*i <= number; i++){
if(number % i == 0){
return false;
}
}
return true;
}
I ran this instead and I'm getting still getting floating point exception: 8, which is really weird. I changed to unsigned long long int but then the number became stored as a negative number -443946297.