Problem 12 : Highly divisible triangular number

The sequence of triangle numbers is generated by adding the natural numbers. So the 7th triangle number would be 1 + 2 + 3 + 4 + 5 + 6 + 7 = 28. The first ten terms would be:

1, 3, 6, 10, 15, 21, 28, 36, 45, 55, …

Let us list the factors of the first seven triangle numbers:

1: 1
3: 1,3
6: 1,2,3,6
10: 1,2,5,10
15: 1,3,5,15
21: 1,3,7,21
28: 1,2,4,7,14,28
We can see that 28 is the first triangle number to have over five divisors.

What is the value of the first triangle number to have over five hundred divisors?

#include <iostream>
#include <cassert>
#include
 
 <cmath>

using namespace std;

class PE0012
{
private:
    int getTriangleNumber(int n);

public:
    int getFactorsOfNumber(int number);
    int findTriangleNumberByFactors(const int numberOfDivisors);
};

int PE0012::getTriangleNumber(int n)
{
    int num = n*(n+1)/2;
    
    return num;
}

int
 
 PE0012::getFactorsOfNumber(int number)
{
    int numberOfFactors = 0;
    double squareRoot = sqrt((double)number);

    for(int i=1;i<=(int)squareRoot;i++)
    {
        if (number % i == 0)
        {
            numberOfFactors++;
            if (number / i != i)
            {
                numberOfFactors++;
            }
        }
    }

    return numberOfFactors;
}

int PE0012::findTriangleNumberByFactors(const int numberOfDivisors)
{    
    int sequence = 7;  // 28
    int triangleNumber;
    int numberOfFactors = 6;  // 28: 1,2,4,7,14,28

    while (numberOfFactors < numberOfDivisors)
    {
        sequence++;
        triangleNumber  = getTriangleNumber(sequence);
        numberOfFactors = getFactorsOfNumber(triangleNumber);
    }

    return triangleNumber;
}

int main()
{
    PE0012 pe0012;

    assert(6 == pe0012.getFactorsOfNumber(28));

    cout << "The first triangle number " << pe0012.findTriangleNumberByFactors(500);
    cout << " has over five hundred divisors." << endl;

    return 0;