901887 divided by 21 
Our goal is to divide 901887 by 21.

Going ahead to step 1:
9 divided by 21 is 0 with a remainder of 9.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 9 leaves us with 9.
Grab the next digit (0) from the dividend, add it to 9, then carry on: 90 / 21

On to step 2:
When dividing 90 by 21, we get 4 with a remainder of 6.
Use 4 as the next digit of our solution. 
Result so far: 4.0
Deduct 84 from 90 and we're left with 6.
Take the next digit (1) from the dividend and append it to 6, then repeat: 61 / 21

Advancing to step 3:
21 goes into 61 2 times with a remainder of 19.
Record the quotient 2 as the next digit in the result. 
Result so far: 42.0
If we subtract 42 from 61, we get 19.
Append the next digit (8) from the dividend to 19 and continue with: 198 / 21

Advancing to step 4:
198 divided by 21 is 9 with a remainder of 9.
Put 9 as the next digit of the answer. 
Result so far: 429.0
If we take 189 away from 198, we end up with 9.
Append the next digit (8) from the dividend to 9 and continue with: 98 / 21

Step 5:
21 goes into 98 4 times with a remainder of 14.
Record the quotient 4 as the next digit in the result. 
Result so far: 4294.0
Subtracting 84 from 98 leaves us with 14.
Bring next digit (7) of the dividend behind the 14 and repeat the process: 147 / 21

Advancing to step 6:
When dividing 147 by 21, we get 7 with a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 42947.0
Deduct 147 from 147 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 7:
If we divide 0 by 21, we get 0 and a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 42947.0
The remainder is 0 after subtracting 0 from 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
If we divide 0 by 21, we get 0 and a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 42947.0
Subtract 0 from 0 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

In conclusion, the division gives 42947.0 with a balance of 0.0.