------
## 最终结论
```python
def smallest_prime_palindrome(N):
    def is_prime(num):
        if num <= 1:
            return False
        if num <= 3:
            return True
        if num % 2 == 0 or num % 3 == 0:
            return False
        i = 5
        while i * i <= num:
            if num % i == 0 or num % (i + 2) == 0:
                return False
            i += 6
        return True

    def is_palindrome(num):
        return str(num) == str(num)[::-1]

    while True:
        if is_prime(N) and is_palindrome(N):
            return N
        N += 1

# Example usage:
print(smallest_prime_palindrome(6))   # Output: 7
print(smallest_prime_palindrome(8))   # Output: 11
print(smallest_prime_palindrome(13))  # Output: 101
```