18431 ÷ 9 = 2047 R8
Alright, let's work through the division of 18431 by 9 step by step.

Step 1:
9 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 1 to get 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 9

Step 2:
9 goes into 18 2 times with a remainder of 0.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 18 from 18 to get 0.
Bring next digit (4) of the dividend behind the 0 and repeat the process: 4 / 9

Step 3:
9 goes into 4 0 times with a remainder of 4.
Write down 0 as next digit of of the result. 
Result so far: 20
Subtract 0 from 4 to get 4.
Bring next digit (3) of the dividend behind the 4 and repeat the process: 43 / 9

Step 4:
9 goes into 43 4 times with a remainder of 7.
Write down 4 as next digit of of the result. 
Result so far: 204
Subtract 36 from 43 to get 7.
Bring next digit (1) of the dividend behind the 7 and repeat the process: 71 / 9

Step 5:
9 goes into 71 7 times with a remainder of 8.
Write down 7 as next digit of of the result. 
Result so far: 2047
Subtract 63 from 71 to get 8.

The final result is 2047 with a remainder of 8.