We divide 99573891 by 1
We want to figure out the number of times 99573891 can be divided by 1.

Going ahead to step 1:
9 divided by 1 is 9 with a remainder of 0.
The number 9 becomes the next digit in our result. 
Result so far: 9.0
If we take 9 away from 9, we end up with 0.
Append the next digit (9) from the dividend to 0 and continue with: 9 / 1

Moving on to step 2:
9 divided by 1 is 9 with a remainder of 0.
Use 9 as the next digit of our solution. 
Result so far: 99.0
Deduct 9 from 9 and we're left with 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 1

On to step 3:
5 divided by 1 is 5 with a remainder of 0.
Put 5 as the next digit of the answer. 
Result so far: 995.0
Subtracting 5 from 5 leaves us with 0.
Fetch the next digit (7) from the dividend, attach it to 0 and continue: 7 / 1

Step 4:
1 goes into 7 7 times with a remainder of 0.
Record the quotient 7 as the next digit in the result. 
Result so far: 9957.0
If we subtract 7 from 7, we get 0.
Append the next digit (3) from the dividend to 0 and continue with: 3 / 1

Step 5:
1 can be fit into 3 3 times, resulting in a remainder of 0.
Put 3 as the next digit of the answer. 
Result so far: 99573.0
Deduct 3 from 3 and we're left with 0.
Bring next digit (8) of the dividend behind the 0 and repeat the process: 8 / 1

Moving on to step 6:
1 goes into 8 8 times with a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 995738.0
The remainder is 0 after subtracting 8 from 8.
Include the next digit (9) from the dividend after 0, then repeat: 9 / 1

Step 7:
9 divided by 1 is 9 with a remainder of 0.
Use 9 as the next digit of our solution. 
Result so far: 9957389.0
Subtracting 9 from 9 leaves us with 0.
Include the next digit (1) from the dividend after 0, then repeat: 1 / 1

On to step 8:
The number 1 fits into 1 1 times, leaving a remainder of 0.
The next digit of our result is 1. 
Result so far: 99573891.0
The remainder is 0 after subtracting 1 from 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
When dividing 0 by 1, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 99573891.0
If we take 0 away from 0, we end up 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.

Let's proceed to step 10:
1 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 99573891.0
Subtracting 0 from 0 leaves us 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.

After the division, we end up with 99573891.0 and a remainder of 0.0.