We look at the division of 20522439 by 21 
Let's see how many times 21 fits into 20522439.

Let's proceed to step 1:
2 divided by 21 is 0 with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Append the next digit (0) from the dividend to 2 and continue with: 20 / 21

Moving on to step 2:
20 divided by 21 is 0 with a remainder of 20.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 20 leaves us with 20.
Take the next digit (5) from the dividend and append it to 20, then repeat: 205 / 21

Going ahead to step 3:
When dividing 205 by 21, we get 9 with a remainder of 16.
Write down 9 as next digit of the result. 
Result so far: 9.0
Subtracting 189 from 205 leaves us with 16.
Append the next digit (2) from the dividend to 16 and continue with: 162 / 21

Advancing to step 4:
The number 21 fits into 162 7 times, leaving a remainder of 15.
The next digit of our result is 7. 
Result so far: 97.0
Subtract 147 from 162 to get 15.
Grab the next digit (2) from the dividend, add it to 15, then carry on: 152 / 21

Advancing to step 5:
If we divide 152 by 21, we get 7 and a remainder of 5.
The number 7 becomes the next digit in our result. 
Result so far: 977.0
If we take 147 away from 152, we end up with 5.
Take the next digit (4) from the dividend and append it to 5, then repeat: 54 / 21

Let's proceed to step 6:
54 divided by 21 is 2 with a remainder of 12.
Use 2 as the next digit of our solution. 
Result so far: 9772.0
The remainder is 12 after subtracting 42 from 54.
Take the next digit (3) from the dividend and append it to 12, then repeat: 123 / 21

On to step 7:
21 goes into 123 5 times with a remainder of 18.
The number 5 becomes the next digit in our result. 
Result so far: 97725.0
The remainder is 18 after subtracting 105 from 123.
Grab the next digit (9) from the dividend, add it to 18, then carry on: 189 / 21

Going ahead to step 8:
189 divided by 21 is 9 with a remainder of 0.
Record the quotient 9 as the next digit in the result. 
Result so far: 977259.0
If we subtract 189 from 189, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
If we divide 0 by 21, we get 0 and a remainder of 0.
The number 0 becomes the next digit in our result. 
Result so far: 977259.0
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 10:
When dividing 0 by 21, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 977259.0
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.

Our division results in 977259.0 with a remaining 0.0.