21121 ÷ 9 = 2346 R7
Alright, let's work through the division of 21121 by 9 step by step.

Step 1:
9 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 2 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 9

Step 2:
9 goes into 21 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 2
Subtract 18 from 21 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 9

Step 3:
9 goes into 31 3 times with a remainder of 4.
Write down 3 as next digit of of the result. 
Result so far: 23
Subtract 27 from 31 to get 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 9

Step 4:
9 goes into 42 4 times with a remainder of 6.
Write down 4 as next digit of of the result. 
Result so far: 234
Subtract 36 from 42 to get 6.
Bring next digit (1) of the dividend behind the 6 and repeat the process: 61 / 9

Step 5:
9 goes into 61 6 times with a remainder of 7.
Write down 6 as next digit of of the result. 
Result so far: 2346
Subtract 54 from 61 to get 7.

The final result is 2346 with a remainder of 7.