Let's divide 20409217 by 21
We want to figure out the number of times 20409217 can be divided by 21.

Moving on to step 1:
When dividing 2 by 21, we get 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Append the next digit (0) from the dividend to 2 and continue with: 20 / 21

Step 2:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 20 leaves us with 20.
Include the next digit (4) from the dividend after 20, then repeat: 204 / 21

Moving on to step 3:
204 divided by 21 is 9 with a remainder of 15.
The next digit of our result is 9. 
Result so far: 9.0
If we subtract 189 from 204, we get 15.
Take the next digit (0) from the dividend and append it to 15, then repeat: 150 / 21

Step 4:
21 goes into 150 7 times with a remainder of 3.
Write down 7 as next digit of the result. 
Result so far: 97.0
If we subtract 147 from 150, we get 3.
Append the next digit (9) from the dividend to 3 and continue with: 39 / 21

Moving on to step 5:
The number 21 fits into 39 1 times, leaving a remainder of 18.
Use 1 as the next digit of our solution. 
Result so far: 971.0
If we take 21 away from 39, we end up with 18.
Append the next digit (2) from the dividend to 18 and continue with: 182 / 21

Advancing to step 6:
When dividing 182 by 21, we get 8 with a remainder of 14.
The next digit of our result is 8. 
Result so far: 9718.0
Subtract 168 from 182 to get 14.
Include the next digit (1) from the dividend after 14, then repeat: 141 / 21

Going ahead to step 7:
21 goes into 141 6 times with a remainder of 15.
Put 6 as the next digit of the answer. 
Result so far: 97186.0
Subtracting 126 from 141 leaves us with 15.
Append the next digit (7) from the dividend to 15 and continue with: 157 / 21

Moving on to step 8:
157 divided by 21 is 7 with a remainder of 10.
Record the quotient 7 as the next digit in the result. 
Result so far: 971867.0
Subtracting 147 from 157 leaves us with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 9:
When dividing 100 by 21, we get 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 971867.4
Subtract 84 from 100 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 10:
160 divided by 21 is 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 971867.47
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 11:
If we divide 130 by 21, we get 6 and a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 971867.476
Deduct 126 from 130 and we're left with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 12:
The number 21 fits into 40 1 times, leaving a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 971867.4761
If we subtract 21 from 40, we get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Let's proceed to step 13:
21 goes into 190 9 times with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 971867.47619
The remainder is 1 after subtracting 189 from 190.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 14:
21 can be fit into 10 0 times, resulting in a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 971867.47619
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 15:
21 goes into 100 4 times with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 971867.4761904
If we subtract 84 from 100, we get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 16:
160 divided by 21 is 7 with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 971867.47619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

The final outcome is 971867.47619047, with a leftover of 1.3e-08.