21051579 divided by 818 
We want to figure out the number of times 21051579 can be divided by 818.

On to step 1:
When dividing 2 by 818, we get 0 with a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 818

Moving on to step 2:
When dividing 21 by 818, we get 0 with a remainder of 21.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Bring next digit (0) of the dividend behind the 21 and repeat the process: 210 / 818

Advancing to step 3:
If we divide 210 by 818, we get 0 and a remainder of 210.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
If we subtract 0 from 210, we get 210.
Grab the next digit (5) from the dividend, add it to 210, then carry on: 2105 / 818

Going ahead to step 4:
When dividing 2105 by 818, we get 2 with a remainder of 469.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
If we subtract 1636 from 2105, we get 469.
Bring next digit (1) of the dividend behind the 469 and repeat the process: 4691 / 818

Step 5:
4691 divided by 818 is 5 with a remainder of 601.
The next digit of our result is 5. 
Result so far: 25.0
Subtracting 4090 from 4691 leaves us with 601.
Include the next digit (5) from the dividend after 601, then repeat: 6015 / 818

Advancing to step 6:
If we divide 6015 by 818, we get 7 and a remainder of 289.
The number 7 becomes the next digit in our result. 
Result so far: 257.0
Subtract 5726 from 6015 to get 289.
Grab the next digit (7) from the dividend, add it to 289, then carry on: 2897 / 818

Moving on to step 7:
818 can be fit into 2897 3 times, resulting in a remainder of 443.
Use 3 as the next digit of our solution. 
Result so far: 2573.0
Subtracting 2454 from 2897 leaves us with 443.
Fetch the next digit (9) from the dividend, attach it to 443 and continue: 4439 / 818

Step 8:
The number 818 fits into 4439 5 times, leaving a remainder of 349.
Write down 5 as next digit of the result. 
Result so far: 25735.0
If we subtract 4090 from 4439, we get 349.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3490, and continue the process.

On to step 9:
818 can be fit into 3490 4 times, resulting in a remainder of 218.
The number 4 becomes the next digit in our result. 
Result so far: 25735.4
Subtracting 3272 from 3490 leaves us with 218.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2180, and continue the process.

Step 10:
818 can be fit into 2180 2 times, resulting in a remainder of 544.
Write down 2 as next digit of the result. 
Result so far: 25735.42
If we subtract 1636 from 2180, we get 544.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5440, and continue the process.

Advancing to step 11:
818 goes into 5440 6 times with a remainder of 532.
Record the quotient 6 as the next digit in the result. 
Result so far: 25735.426
The remainder is 532 after subtracting 4908 from 5440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5320, and continue the process.

Advancing to step 12:
If we divide 5320 by 818, we get 6 and a remainder of 412.
Write down 6 as next digit of the result. 
Result so far: 25735.4266
Subtracting 4908 from 5320 leaves us with 412.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4120, and continue the process.

The final result is 25735.4266 with a remainder of 0.00412.