We look at the division of 496639 by 21 
We're looking to find how many times 21 goes into 496639.

Moving on to step 1:
The number 21 fits into 4 0 times, leaving a remainder of 4.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Fetch the next digit (9) from the dividend, attach it to 4 and continue: 49 / 21

Moving on to step 2:
21 goes into 49 2 times with a remainder of 7.
The next digit of our result is 2. 
Result so far: 2.0
Subtract 42 from 49 to get 7.
Include the next digit (6) from the dividend after 7, then repeat: 76 / 21

Step 3:
If we divide 76 by 21, we get 3 and a remainder of 13.
Use 3 as the next digit of our solution. 
Result so far: 23.0
Subtracting 63 from 76 leaves us with 13.
Fetch the next digit (6) from the dividend, attach it to 13 and continue: 136 / 21

Moving on to step 4:
21 can be fit into 136 6 times, resulting in a remainder of 10.
The number 6 becomes the next digit in our result. 
Result so far: 236.0
Subtract 126 from 136 to get 10.
Append the next digit (3) from the dividend to 10 and continue with: 103 / 21

On to step 5:
If we divide 103 by 21, we get 4 and a remainder of 19.
Record the quotient 4 as the next digit in the result. 
Result so far: 2364.0
If we take 84 away from 103, we end up with 19.
Bring next digit (9) of the dividend behind the 19 and repeat the process: 199 / 21

Moving on to step 6:
When dividing 199 by 21, we get 9 with a remainder of 10.
Use 9 as the next digit of our solution. 
Result so far: 23649.0
Deduct 189 from 199 and we're left 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.

Going ahead to step 7:
100 divided by 21 is 4 with a remainder of 16.
The number 4 becomes the next digit in our result. 
Result so far: 23649.4
If we take 84 away from 100, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 8:
21 goes into 160 7 times with a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 23649.47
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

On to step 9:
130 divided by 21 is 6 with a remainder of 4.
Record the quotient 6 as the next digit in the result. 
Result so far: 23649.476
The remainder is 4 after subtracting 126 from 130.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Moving on to step 10:
When dividing 40 by 21, we get 1 with a remainder of 19.
Use 1 as the next digit of our solution. 
Result so far: 23649.4761
Subtract 21 from 40 to 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 11:
21 goes into 190 9 times with a remainder of 1.
Write down 9 as next digit of the result. 
Result so far: 23649.47619
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 12:
10 divided by 21 is 0 with a remainder of 10.
Write down 0 as next digit of the result. 
Result so far: 23649.47619
Subtracting 0 from 10 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.

On to step 13:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Put 4 as the next digit of the answer. 
Result so far: 23649.4761904
The remainder is 16 after subtracting 84 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 14:
21 goes into 160 7 times with a remainder of 13.
Record the quotient 7 as the next digit in the result. 
Result so far: 23649.47619047
Subtract 147 from 160 to 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.

In conclusion, the division gives 23649.47619047 with a balance of 1.3e-08.