5247

5247 = 3 x 3 x 11 x 53.

5247 is the number of ordered ways to write 1 as a sum of reciprocals of integers no larger than 10.

5247 has three 1s and three 3s in its base 4 representation (A045127).

5247 divides 23¹² - 1.

5247 is a number that cannot be written as a sum of three squares.

Source: What's Special About This Number?