91591728 divided by 60 
We want to figure out the number of times 91591728 can be divided by 60.

Step 1:
If we divide 9 by 60, we get 0 and a remainder of 9.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 9, we end up with 9.
Include the next digit (1) from the dividend after 9, then repeat: 91 / 60

Advancing to step 2:
The number 60 fits into 91 1 times, leaving a remainder of 31.
Put 1 as the next digit of the answer. 
Result so far: 1.0
The remainder is 31 after subtracting 60 from 91.
Include the next digit (5) from the dividend after 31, then repeat: 315 / 60

Advancing to step 3:
When dividing 315 by 60, we get 5 with a remainder of 15.
The number 5 becomes the next digit in our result. 
Result so far: 15.0
Subtract 300 from 315 to get 15.
Include the next digit (9) from the dividend after 15, then repeat: 159 / 60

Advancing to step 4:
159 divided by 60 is 2 with a remainder of 39.
Put 2 as the next digit of the answer. 
Result so far: 152.0
Subtracting 120 from 159 leaves us with 39.
Fetch the next digit (1) from the dividend, attach it to 39 and continue: 391 / 60

On to step 5:
The number 60 fits into 391 6 times, leaving a remainder of 31.
Write down 6 as next digit of the result. 
Result so far: 1526.0
The remainder is 31 after subtracting 360 from 391.
Bring next digit (7) of the dividend behind the 31 and repeat the process: 317 / 60

Moving on to step 6:
If we divide 317 by 60, we get 5 and a remainder of 17.
Use 5 as the next digit of our solution. 
Result so far: 15265.0
The remainder is 17 after subtracting 300 from 317.
Grab the next digit (2) from the dividend, add it to 17, then carry on: 172 / 60

Let's proceed to step 7:
If we divide 172 by 60, we get 2 and a remainder of 52.
Record the quotient 2 as the next digit in the result. 
Result so far: 152652.0
If we subtract 120 from 172, we get 52.
Append the next digit (8) from the dividend to 52 and continue with: 528 / 60

Advancing to step 8:
If we divide 528 by 60, we get 8 and a remainder of 48.
Record the quotient 8 as the next digit in the result. 
Result so far: 1526528.0
Deduct 480 from 528 and we're left with 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Going ahead to step 9:
60 goes into 480 8 times with a remainder of 0.
The next digit of our result is 8. 
Result so far: 1526528.8
The remainder is 0 after subtracting 480 from 480.
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:
When dividing 0 by 60, we get 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 1526528.8
If we subtract 0 from 0, we 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.

Moving on to step 11:
0 divided by 60 is 0 with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 1526528.8
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.

After the division, we end up with 1526528.8 and a remainder of 0.0.