Let n = 4q + 3. Then 2n = 8q + 6   = 4(2q + 1 ) + 2.

Thus, when 2n is divided by 4, the remainder is 2.

Let 4300731 - x = 2535618

Then x, = 4300731 - 2535618 = 1765113

On dividing we get, 

 88) 9217 (104
     88
     ----
      417
      352
      ----
       65
      ----
  
 Therefore, Required number = 9217 + (88 - 65) // Because (88 - 65) < 65.
                            = 9217 + 23
                            = 9240.      

639 is not divisible by 7

2079 is divisible by each of 3, 7, 9, 11.