81221409 ÷ 639 
Let's see how many times 639 fits into 81221409.

Advancing to step 1:
8 divided by 639 is 0 with a remainder of 8.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 639

Going ahead to step 2:
When dividing 81 by 639, we get 0 with a remainder of 81.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 81 to get 81.
Fetch the next digit (2) from the dividend, attach it to 81 and continue: 812 / 639

Let's proceed to step 3:
When dividing 812 by 639, we get 1 with a remainder of 173.
Write down 1 as next digit of the result. 
Result so far: 1.0
Subtracting 639 from 812 leaves us with 173.
Append the next digit (2) from the dividend to 173 and continue with: 1732 / 639

Advancing to step 4:
The number 639 fits into 1732 2 times, leaving a remainder of 454.
The next digit of our result is 2. 
Result so far: 12.0
Subtracting 1278 from 1732 leaves us with 454.
Fetch the next digit (1) from the dividend, attach it to 454 and continue: 4541 / 639

Step 5:
If we divide 4541 by 639, we get 7 and a remainder of 68.
Put 7 as the next digit of the answer. 
Result so far: 127.0
Deduct 4473 from 4541 and we're left with 68.
Fetch the next digit (4) from the dividend, attach it to 68 and continue: 684 / 639

Let's proceed to step 6:
639 goes into 684 1 times with a remainder of 45.
Record the quotient 1 as the next digit in the result. 
Result so far: 1271.0
Deduct 639 from 684 and we're left with 45.
Fetch the next digit (0) from the dividend, attach it to 45 and continue: 450 / 639

Going ahead to step 7:
639 can be fit into 450 0 times, resulting in a remainder of 450.
Put 0 as the next digit of the answer. 
Result so far: 12710.0
Subtract 0 from 450 to get 450.
Take the next digit (9) from the dividend and append it to 450, then repeat: 4509 / 639

Moving on to step 8:
When dividing 4509 by 639, we get 7 with a remainder of 36.
Use 7 as the next digit of our solution. 
Result so far: 127107.0
If we subtract 4473 from 4509, we get 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

Let's proceed to step 9:
639 goes into 360 0 times with a remainder of 360.
The next digit of our result is 0. 
Result so far: 127107.0
If we subtract 0 from 360, we get 360.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

Let's proceed to step 10:
639 can be fit into 3600 5 times, resulting in a remainder of 405.
Record the quotient 5 as the next digit in the result. 
Result so far: 127107.05
Subtract 3195 from 3600 to get 405.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4050, and continue the process.

Advancing to step 11:
The number 639 fits into 4050 6 times, leaving a remainder of 216.
The next digit of our result is 6. 
Result so far: 127107.056
Subtracting 3834 from 4050 leaves us with 216.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2160, and continue the process.

Going ahead to step 12:
639 goes into 2160 3 times with a remainder of 243.
Write down 3 as next digit of the result. 
Result so far: 127107.0563
The remainder is 243 after subtracting 1917 from 2160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2430, and continue the process.

Going ahead to step 13:
When dividing 2430 by 639, we get 3 with a remainder of 513.
Put 3 as the next digit of the answer. 
Result so far: 127107.05633
Subtract 1917 from 2430 to get 513.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5130, and continue the process.

After the division, we end up with 127107.05633 and a remainder of 0.000513.