Hello,

I am trying to write a algoritm that calculates the second largest divisor of a number. But i have absolutely no idea what calculations are required for this.

```
for (ulong i = 1; i < Number; i++)
{
Number = .....?
}
```

Already know the largest common diviser of 2 numbers, but i cannot find anything considering the second largest divisor of a number.

Kind regards.