IQ Test · Adults Question 13

What number should replace the question mark? The numbers around the border are: top row 4, 9, 13, 5, 86, 2, 7; left column 82, 79, 6, 35; right column 9, 24, 63, 18; bottom row 1, 6, 37, 8, 49, 2, ?. Answer with a natural number.