583091 ÷ 21 
We want to figure out the number of times 583091 can be divided by 21.

Going ahead to step 1:
5 divided by 21 is 0 with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Bring next digit (8) of the dividend behind the 5 and repeat the process: 58 / 21

Let's proceed to step 2:
When dividing 58 by 21, we get 2 with a remainder of 16.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 42 from 58 and we're left with 16.
Append the next digit (3) from the dividend to 16 and continue with: 163 / 21

On to step 3:
21 goes into 163 7 times with a remainder of 16.
The number 7 becomes the next digit in our result. 
Result so far: 27.0
Deduct 147 from 163 and we're left with 16.
Take the next digit (0) from the dividend and append it to 16, then repeat: 160 / 21

Going ahead to step 4:
160 divided by 21 is 7 with a remainder of 13.
Write down 7 as next digit of the result. 
Result so far: 277.0
The remainder is 13 after subtracting 147 from 160.
Bring next digit (9) of the dividend behind the 13 and repeat the process: 139 / 21

Step 5:
The number 21 fits into 139 6 times, leaving a remainder of 13.
The number 6 becomes the next digit in our result. 
Result so far: 2776.0
Deduct 126 from 139 and we're left with 13.
Bring next digit (1) of the dividend behind the 13 and repeat the process: 131 / 21

Moving on to step 6:
The number 21 fits into 131 6 times, leaving a remainder of 5.
Record the quotient 6 as the next digit in the result. 
Result so far: 27766.0
If we subtract 126 from 131, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

On to step 7:
21 can be fit into 50 2 times, resulting in a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 27766.2
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 8:
The number 21 fits into 80 3 times, leaving a remainder of 17.
The next digit of our result is 3. 
Result so far: 27766.23
Deduct 63 from 80 and we're left with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 9:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 27766.238
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Moving on to step 10:
21 can be fit into 20 0 times, resulting in a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 27766.238
If we subtract 0 from 20, we get 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Advancing to step 11:
200 divided by 21 is 9 with a remainder of 11.
Write down 9 as next digit of the result. 
Result so far: 27766.23809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Advancing to step 12:
110 divided by 21 is 5 with a remainder of 5.
The number 5 becomes the next digit in our result. 
Result so far: 27766.238095
If we subtract 105 from 110, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 13:
50 divided by 21 is 2 with a remainder of 8.
The number 2 becomes the next digit in our result. 
Result so far: 27766.2380952
If we subtract 42 from 50, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Let's proceed to step 14:
80 divided by 21 is 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 27766.23809523
Subtracting 63 from 80 leaves us with 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

In conclusion, the division gives 27766.23809523 with a balance of 1.7e-08.