Let's divide 21217531 by 144
Let's see how many times 144 fits into 21217531.

Step 1:
The number 144 fits into 2 0 times, leaving a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 2 to get 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 144

On to step 2:
The number 144 fits into 21 0 times, leaving a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Fetch the next digit (2) from the dividend, attach it to 21 and continue: 212 / 144

Advancing to step 3:
212 divided by 144 is 1 with a remainder of 68.
Put 1 as the next digit of the answer. 
Result so far: 1.0
If we subtract 144 from 212, we get 68.
Bring next digit (1) of the dividend behind the 68 and repeat the process: 681 / 144

Moving on to step 4:
When dividing 681 by 144, we get 4 with a remainder of 105.
Put 4 as the next digit of the answer. 
Result so far: 14.0
Deduct 576 from 681 and we're left with 105.
Take the next digit (7) from the dividend and append it to 105, then repeat: 1057 / 144

On to step 5:
144 can be fit into 1057 7 times, resulting in a remainder of 49.
Write down 7 as next digit of the result. 
Result so far: 147.0
If we take 1008 away from 1057, we end up with 49.
Fetch the next digit (5) from the dividend, attach it to 49 and continue: 495 / 144

Going ahead to step 6:
The number 144 fits into 495 3 times, leaving a remainder of 63.
Record the quotient 3 as the next digit in the result. 
Result so far: 1473.0
If we subtract 432 from 495, we get 63.
Take the next digit (3) from the dividend and append it to 63, then repeat: 633 / 144

Moving on to step 7:
When dividing 633 by 144, we get 4 with a remainder of 57.
Use 4 as the next digit of our solution. 
Result so far: 14734.0
The remainder is 57 after subtracting 576 from 633.
Take the next digit (1) from the dividend and append it to 57, then repeat: 571 / 144

On to step 8:
If we divide 571 by 144, we get 3 and a remainder of 139.
Record the quotient 3 as the next digit in the result. 
Result so far: 147343.0
If we subtract 432 from 571, we get 139.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1390, and continue the process.

Advancing to step 9:
If we divide 1390 by 144, we get 9 and a remainder of 94.
The next digit of our result is 9. 
Result so far: 147343.9
If we subtract 1296 from 1390, we get 94.
Since there are no more digits in the dividend, we add a zero to the remainder making it 940, and continue the process.

Advancing to step 10:
144 can be fit into 940 6 times, resulting in a remainder of 76.
Write down 6 as next digit of the result. 
Result so far: 147343.96
If we subtract 864 from 940, we get 76.
Since there are no more digits in the dividend, we add a zero to the remainder making it 760, and continue the process.

Moving on to step 11:
When dividing 760 by 144, we get 5 with a remainder of 40.
The number 5 becomes the next digit in our result. 
Result so far: 147343.965
Subtract 720 from 760 to get 40.
Since there are no more digits in the dividend, we add a zero to the remainder making it 400, and continue the process.

Moving on to step 12:
The number 144 fits into 400 2 times, leaving a remainder of 112.
Use 2 as the next digit of our solution. 
Result so far: 147343.9652
If we subtract 288 from 400, we get 112.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1120, and continue the process.

Moving on to step 13:
144 goes into 1120 7 times with a remainder of 112.
The next digit of our result is 7. 
Result so far: 147343.96527
If we subtract 1008 from 1120, we get 112.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1120, and continue the process.

Going ahead to step 14:
144 can be fit into 1120 7 times, resulting in a remainder of 112.
The next digit of our result is 7. 
Result so far: 147343.965277
If we subtract 1008 from 1120, we get 112.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1120, and continue the process.

The final outcome is 147343.965277, with a leftover of 1.12e-05.