139617 divided by 21 
We're looking to find how many times 21 goes into 139617.

On to step 1:
21 can be fit into 1 0 times, resulting in a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 1 leaves us with 1.
Grab the next digit (3) from the dividend, add it to 1, then carry on: 13 / 21

Advancing to step 2:
The number 21 fits into 13 0 times, leaving a remainder of 13.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 13 and we're left with 13.
Fetch the next digit (9) from the dividend, attach it to 13 and continue: 139 / 21

Step 3:
139 divided by 21 is 6 with a remainder of 13.
Write down 6 as next digit of the result. 
Result so far: 6.0
If we subtract 126 from 139, we get 13.
Append the next digit (6) from the dividend to 13 and continue with: 136 / 21

Step 4:
When dividing 136 by 21, we get 6 with a remainder of 10.
Write down 6 as next digit of the result. 
Result so far: 66.0
Subtract 126 from 136 to get 10.
Append the next digit (1) from the dividend to 10 and continue with: 101 / 21

On to step 5:
The number 21 fits into 101 4 times, leaving a remainder of 17.
Put 4 as the next digit of the answer. 
Result so far: 664.0
Subtract 84 from 101 to get 17.
Append the next digit (7) from the dividend to 17 and continue with: 177 / 21

Let's proceed to step 6:
The number 21 fits into 177 8 times, leaving a remainder of 9.
The number 8 becomes the next digit in our result. 
Result so far: 6648.0
Subtract 168 from 177 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 7:
21 goes into 90 4 times with a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 6648.4
Subtract 84 from 90 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 8:
When dividing 60 by 21, we get 2 with a remainder of 18.
Write down 2 as next digit of the result. 
Result so far: 6648.42
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 9:
21 can be fit into 180 8 times, resulting in a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 6648.428
Deduct 168 from 180 and we're left with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 10:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 6648.4285
Subtract 105 from 120 to get 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 11:
21 goes into 150 7 times with a remainder of 3.
The next digit of our result is 7. 
Result so far: 6648.42857
Subtracting 147 from 150 leaves us with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 12:
If we divide 30 by 21, we get 1 and a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 6648.428571
Subtract 21 from 30 to get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 13:
The number 21 fits into 90 4 times, leaving a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 6648.4285714
Subtracting 84 from 90 leaves us with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 14:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 6648.42857142
Deduct 42 from 60 and we're left with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

The quotient of the division is 6648.42857142, and the remainder is 1.8e-08.