------
## 最终结论
```python
def first_Factorial_Divisible_Number(x):
    n = 1
    factorial = 1
    while True:
        factorial *= n
        if factorial % x == 0:
            return n
        n += 1

# Test cases
assert first_Factorial_Divisible_Number(10) == 5
assert first_Factorial_Divisible_Number(15) == 5
assert first_Factorial_Divisible_Number(5) == 4
```