def _is_lychrel_number(number, max_iterations):
if max_iterations == 0:
return True
else:
iteration = number + int(str(number)[::-1])
if is_palindrome(iteration):
return False
else:
return _is_lychrel_number(iteration, max_iterations - 1)
def largest_palindrome(number_of_digits_in_product):
largest_product = pow(10, number_of_digits_in_product) - 1
smallest_product = pow(10, number_of_digits_in_product - 1)
_largest_palindrome = -1
for i in range(largest_product, smallest_product, -1):
for j in range(i, smallest_product, -1):
if is_palindrome(i * j):
_largest_palindrome = max(_largest_palindrome, i * j)
break
return _largest_palindrome