Largest palindrome which is product of two n-digit numbers

Given a value n, find out the largest palindrome number which is product of two n digit numbers.

Examples : 

Input : n = 2
Output : 9009 
9009 is the largest number which is product of two 
2-digit numbers. 9009 = 91*99.

Input : n = 3
Output : 906609

Below are steps to find the required number. 

1. Find a lower limit on n digit numbers. For example, for n = 2, lower_limit is 10.
2. Find an upper limit on n digit numbers. For example, for n = 2, upper_limit is 99.
3. Consider all pairs of numbers wherever number lies in range [lower_limit, upper_limit]

Below is the implementation of above steps. 

Output :

9009

Time Complexity: O(n*n*log₁₀(product)), where n is the upper limit calculated and product is (product of two n-digit numbers)
Auxiliary Space: O(1), as no extra space is required|
The approach used in this post is simple and straightforward. Please comment if you find a better approach.