818181 divided by 21 
We're looking to find how many times 21 goes into 818181.

Advancing to step 1:
21 goes into 8 0 times with a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Fetch the next digit (1) from the dividend, attach it to 8 and continue: 81 / 21

Going ahead to step 2:
81 divided by 21 is 3 with a remainder of 18.
Put 3 as the next digit of the answer. 
Result so far: 3.0
The remainder is 18 after subtracting 63 from 81.
Grab the next digit (8) from the dividend, add it to 18, then carry on: 188 / 21

On to step 3:
21 goes into 188 8 times with a remainder of 20.
Write down 8 as next digit of the result. 
Result so far: 38.0
Subtract 168 from 188 to get 20.
Include the next digit (1) from the dividend after 20, then repeat: 201 / 21

Step 4:
If we divide 201 by 21, we get 9 and a remainder of 12.
Record the quotient 9 as the next digit in the result. 
Result so far: 389.0
Subtract 189 from 201 to get 12.
Append the next digit (8) from the dividend to 12 and continue with: 128 / 21

Step 5:
When dividing 128 by 21, we get 6 with a remainder of 2.
The next digit of our result is 6. 
Result so far: 3896.0
If we subtract 126 from 128, we get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 21

Advancing to step 6:
When dividing 21 by 21, we get 1 with a remainder of 0.
The number 1 becomes the next digit in our result. 
Result so far: 38961.0
The remainder is 0 after subtracting 21 from 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Let's proceed to step 7:
21 can be fit into 0 0 times, resulting in a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 38961.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 8:
The number 21 fits into 0 0 times, leaving a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 38961.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 38961.0, and the remainder is 0.0.