We look at the division of 21691248 by 405 
We're looking to find how many times 405 goes into 21691248.

Going ahead to step 1:
If we divide 2 by 405, we get 0 and a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 405

Let's proceed to step 2:
The number 405 fits into 21 0 times, leaving a remainder of 21.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 21, we end up with 21.
Fetch the next digit (6) from the dividend, attach it to 21 and continue: 216 / 405

Moving on to step 3:
The number 405 fits into 216 0 times, leaving a remainder of 216.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 216, we end up with 216.
Append the next digit (9) from the dividend to 216 and continue with: 2169 / 405

Step 4:
If we divide 2169 by 405, we get 5 and a remainder of 144.
Put 5 as the next digit of the answer. 
Result so far: 5.0
If we take 2025 away from 2169, we end up with 144.
Grab the next digit (1) from the dividend, add it to 144, then carry on: 1441 / 405

Going ahead to step 5:
When dividing 1441 by 405, we get 3 with a remainder of 226.
Put 3 as the next digit of the answer. 
Result so far: 53.0
If we subtract 1215 from 1441, we get 226.
Take the next digit (2) from the dividend and append it to 226, then repeat: 2262 / 405

Advancing to step 6:
405 can be fit into 2262 5 times, resulting in a remainder of 237.
The next digit of our result is 5. 
Result so far: 535.0
Deduct 2025 from 2262 and we're left with 237.
Grab the next digit (4) from the dividend, add it to 237, then carry on: 2374 / 405

Going ahead to step 7:
The number 405 fits into 2374 5 times, leaving a remainder of 349.
The next digit of our result is 5. 
Result so far: 5355.0
If we subtract 2025 from 2374, we get 349.
Fetch the next digit (8) from the dividend, attach it to 349 and continue: 3498 / 405

On to step 8:
405 can be fit into 3498 8 times, resulting in a remainder of 258.
Write down 8 as next digit of the result. 
Result so far: 53558.0
Subtracting 3240 from 3498 leaves us with 258.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2580, and continue the process.

Going ahead to step 9:
When dividing 2580 by 405, we get 6 with a remainder of 150.
Put 6 as the next digit of the answer. 
Result so far: 53558.6
If we subtract 2430 from 2580, we get 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Moving on to step 10:
When dividing 1500 by 405, we get 3 with a remainder of 285.
The number 3 becomes the next digit in our result. 
Result so far: 53558.63
If we subtract 1215 from 1500, we get 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

Step 11:
2850 divided by 405 is 7 with a remainder of 15.
The number 7 becomes the next digit in our result. 
Result so far: 53558.637
If we subtract 2835 from 2850, we get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 12:
When dividing 150 by 405, we get 0 with a remainder of 150.
Write down 0 as next digit of the result. 
Result so far: 53558.637
The remainder is 150 after subtracting 0 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Moving on to step 13:
When dividing 1500 by 405, we get 3 with a remainder of 285.
Write down 3 as next digit of the result. 
Result so far: 53558.63703
Deduct 1215 from 1500 and we're left with 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

Step 14:
405 can be fit into 2850 7 times, resulting in a remainder of 15.
Put 7 as the next digit of the answer. 
Result so far: 53558.637037
Deduct 2835 from 2850 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Moving on to step 15:
If we divide 150 by 405, we get 0 and a remainder of 150.
Record the quotient 0 as the next digit in the result. 
Result so far: 53558.637037
Subtracting 0 from 150 leaves us with 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1500, and continue the process.

Step 16:
The number 405 fits into 1500 3 times, leaving a remainder of 285.
Write down 3 as next digit of the result. 
Result so far: 53558.63703703
The remainder is 285 after subtracting 1215 from 1500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

The final result is 53558.63703703 with a remainder of 2.85e-07.