63866 ÷ 8 = 7983 R2
Let's divide 63866 by 8.

Step 1:
8 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 6 to get 6.
Bring next digit (3) of the dividend behind the 6 and repeat the process: 63 / 8

Step 2:
8 goes into 63 7 times with a remainder of 7.
Write down 7 as next digit of of the result. 
Result so far: 7
Subtract 56 from 63 to get 7.
Bring next digit (8) of the dividend behind the 7 and repeat the process: 78 / 8

Step 3:
8 goes into 78 9 times with a remainder of 6.
Write down 9 as next digit of of the result. 
Result so far: 79
Subtract 72 from 78 to get 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 8

Step 4:
8 goes into 66 8 times with a remainder of 2.
Write down 8 as next digit of of the result. 
Result so far: 798
Subtract 64 from 66 to get 2.
Bring next digit (6) of the dividend behind the 2 and repeat the process: 26 / 8

Step 5:
8 goes into 26 3 times with a remainder of 2.
Write down 3 as next digit of of the result. 
Result so far: 7983
Subtract 24 from 26 to get 2.

The final result is 7983 with a remainder of 2.