21638129 ÷ 166 
We want to figure out the number of times 21638129 can be divided by 166.

Moving on to step 1:
If we divide 2 by 166, we get 0 and a remainder of 2.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 166

Going ahead to step 2:
166 can be fit into 21 0 times, resulting in a remainder of 21.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 21 leaves us with 21.
Take the next digit (6) from the dividend and append it to 21, then repeat: 216 / 166

Step 3:
166 goes into 216 1 times with a remainder of 50.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 50 after subtracting 166 from 216.
Include the next digit (3) from the dividend after 50, then repeat: 503 / 166

Let's proceed to step 4:
166 goes into 503 3 times with a remainder of 5.
Record the quotient 3 as the next digit in the result. 
Result so far: 13.0
Deduct 498 from 503 and we're left with 5.
Grab the next digit (8) from the dividend, add it to 5, then carry on: 58 / 166

Going ahead to step 5:
166 goes into 58 0 times with a remainder of 58.
Record the quotient 0 as the next digit in the result. 
Result so far: 130.0
Deduct 0 from 58 and we're left with 58.
Grab the next digit (1) from the dividend, add it to 58, then carry on: 581 / 166

Let's proceed to step 6:
166 goes into 581 3 times with a remainder of 83.
Record the quotient 3 as the next digit in the result. 
Result so far: 1303.0
The remainder is 83 after subtracting 498 from 581.
Fetch the next digit (2) from the dividend, attach it to 83 and continue: 832 / 166

Moving on to step 7:
166 can be fit into 832 5 times, resulting in a remainder of 2.
The next digit of our result is 5. 
Result so far: 13035.0
The remainder is 2 after subtracting 830 from 832.
Fetch the next digit (9) from the dividend, attach it to 2 and continue: 29 / 166

Advancing to step 8:
The number 166 fits into 29 0 times, leaving a remainder of 29.
Put 0 as the next digit of the answer. 
Result so far: 130350.0
The remainder is 29 after subtracting 0 from 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 290, and continue the process.

Let's proceed to step 9:
When dividing 290 by 166, we get 1 with a remainder of 124.
The number 1 becomes the next digit in our result. 
Result so far: 130350.1
If we subtract 166 from 290, we get 124.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1240, and continue the process.

On to step 10:
If we divide 1240 by 166, we get 7 and a remainder of 78.
The number 7 becomes the next digit in our result. 
Result so far: 130350.17
Subtracting 1162 from 1240 leaves us with 78.
Since there are no more digits in the dividend, we add a zero to the remainder making it 780, and continue the process.

Moving on to step 11:
The number 166 fits into 780 4 times, leaving a remainder of 116.
Record the quotient 4 as the next digit in the result. 
Result so far: 130350.174
The remainder is 116 after subtracting 664 from 780.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1160, and continue the process.

Advancing to step 12:
When dividing 1160 by 166, we get 6 with a remainder of 164.
Use 6 as the next digit of our solution. 
Result so far: 130350.1746
If we subtract 996 from 1160, we get 164.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1640, and continue the process.

On to step 13:
166 goes into 1640 9 times with a remainder of 146.
Use 9 as the next digit of our solution. 
Result so far: 130350.17469
Deduct 1494 from 1640 and we're left with 146.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1460, and continue the process.

Going ahead to step 14:
When dividing 1460 by 166, we get 8 with a remainder of 132.
Write down 8 as next digit of the result. 
Result so far: 130350.174698
If we subtract 1328 from 1460, we get 132.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1320, and continue the process.

On to step 15:
When dividing 1320 by 166, we get 7 with a remainder of 158.
The number 7 becomes the next digit in our result. 
Result so far: 130350.1746987
If we subtract 1162 from 1320, we get 158.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1580, and continue the process.

Advancing to step 16:
When dividing 1580 by 166, we get 9 with a remainder of 86.
The number 9 becomes the next digit in our result. 
Result so far: 130350.17469879
If we subtract 1494 from 1580, we get 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 860, and continue the process.

The final result is 130350.17469879 with a remainder of 8.6e-08.