------
## 最终结论
```python
def max_Prime_Factors(n):
    max_prime = -1
    
    # Remove all even factors of 2
    while n % 2 == 0:
        max_prime = 2
        n //= 2
    
    # Check for odd factors from 3 to sqrt(n)
    for i in range(3, int(n**0.5) + 1, 2):
        while n % i == 0:
            max_prime = i
            n //= i
            
    # Check if remaining number is greater than 2
    if n > 2:
        max_prime = n
        
    return max_prime

# Test cases
assert max_Prime_Factors(15) == 5
assert max_Prime_Factors(6) == 3
assert max_Prime_Factors(2) == 2
```