We're dividing 81265747 by 21 
We want to figure out the number of times 81265747 can be divided by 21.

Advancing to step 1:
The number 21 fits into 8 0 times, leaving a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 8 leaves us with 8.
Append the next digit (1) from the dividend to 8 and continue with: 81 / 21

On to step 2:
21 can be fit into 81 3 times, resulting in a remainder of 18.
Write down 3 as next digit of the result. 
Result so far: 3.0
Subtract 63 from 81 to get 18.
Fetch the next digit (2) from the dividend, attach it to 18 and continue: 182 / 21

Advancing to step 3:
21 can be fit into 182 8 times, resulting in a remainder of 14.
Use 8 as the next digit of our solution. 
Result so far: 38.0
Subtract 168 from 182 to get 14.
Append the next digit (6) from the dividend to 14 and continue with: 146 / 21

Going ahead to step 4:
If we divide 146 by 21, we get 6 and a remainder of 20.
Put 6 as the next digit of the answer. 
Result so far: 386.0
The remainder is 20 after subtracting 126 from 146.
Bring next digit (5) of the dividend behind the 20 and repeat the process: 205 / 21

Moving on to step 5:
If we divide 205 by 21, we get 9 and a remainder of 16.
Use 9 as the next digit of our solution. 
Result so far: 3869.0
Subtract 189 from 205 to get 16.
Include the next digit (7) from the dividend after 16, then repeat: 167 / 21

Going ahead to step 6:
If we divide 167 by 21, we get 7 and a remainder of 20.
Put 7 as the next digit of the answer. 
Result so far: 38697.0
Subtract 147 from 167 to get 20.
Take the next digit (4) from the dividend and append it to 20, then repeat: 204 / 21

Advancing to step 7:
204 divided by 21 is 9 with a remainder of 15.
Use 9 as the next digit of our solution. 
Result so far: 386979.0
Deduct 189 from 204 and we're left with 15.
Fetch the next digit (7) from the dividend, attach it to 15 and continue: 157 / 21

Step 8:
21 goes into 157 7 times with a remainder of 10.
Put 7 as the next digit of the answer. 
Result so far: 3869797.0
If we subtract 147 from 157, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Let's proceed to step 9:
21 goes into 100 4 times with a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 3869797.4
Subtracting 84 from 100 leaves us 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.

Going ahead to step 10:
The number 21 fits into 160 7 times, leaving a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 3869797.47
If we take 147 away from 160, we end up 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.

Moving on to step 11:
130 divided by 21 is 6 with a remainder of 4.
The next digit of our result is 6. 
Result so far: 3869797.476
Subtracting 126 from 130 leaves us 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.
Record the quotient 1 as the next digit in the result. 
Result so far: 3869797.4761
Subtracting 21 from 40 leaves us with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Advancing to step 13:
21 can be fit into 190 9 times, resulting in a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 3869797.47619
Subtracting 189 from 190 leaves us 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.

Moving on to step 14:
When dividing 10 by 21, we get 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 3869797.47619
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 15:
When dividing 100 by 21, we get 4 with a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 3869797.4761904
Subtracting 84 from 100 leaves us 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 16:
When dividing 160 by 21, we get 7 with a remainder of 13.
Use 7 as the next digit of our solution. 
Result so far: 3869797.47619047
Deduct 147 from 160 and we're left 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.

The final outcome is 3869797.47619047, with a leftover of 1.3e-08.