15521669 ÷ 421 
We want to divide 15521669 by 421.

Step 1:
1 divided by 421 is 0 with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (5) from the dividend to 1 and continue with: 15 / 421

Step 2:
421 can be fit into 15 0 times, resulting in a remainder of 15.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 15 after subtracting 0 from 15.
Fetch the next digit (5) from the dividend, attach it to 15 and continue: 155 / 421

Let's proceed to step 3:
421 can be fit into 155 0 times, resulting in a remainder of 155.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 155 to get 155.
Grab the next digit (2) from the dividend, add it to 155, then carry on: 1552 / 421

Step 4:
If we divide 1552 by 421, we get 3 and a remainder of 289.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtracting 1263 from 1552 leaves us with 289.
Grab the next digit (1) from the dividend, add it to 289, then carry on: 2891 / 421

Step 5:
The number 421 fits into 2891 6 times, leaving a remainder of 365.
Put 6 as the next digit of the answer. 
Result so far: 36.0
Deduct 2526 from 2891 and we're left with 365.
Bring next digit (6) of the dividend behind the 365 and repeat the process: 3656 / 421

Advancing to step 6:
421 can be fit into 3656 8 times, resulting in a remainder of 288.
Use 8 as the next digit of our solution. 
Result so far: 368.0
Subtracting 3368 from 3656 leaves us with 288.
Grab the next digit (6) from the dividend, add it to 288, then carry on: 2886 / 421

Moving on to step 7:
421 can be fit into 2886 6 times, resulting in a remainder of 360.
Write down 6 as next digit of the result. 
Result so far: 3686.0
If we take 2526 away from 2886, we end up with 360.
Grab the next digit (9) from the dividend, add it to 360, then carry on: 3609 / 421

Advancing to step 8:
The number 421 fits into 3609 8 times, leaving a remainder of 241.
Write down 8 as next digit of the result. 
Result so far: 36868.0
If we take 3368 away from 3609, we end up with 241.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2410, and continue the process.

Let's proceed to step 9:
421 can be fit into 2410 5 times, resulting in a remainder of 305.
Put 5 as the next digit of the answer. 
Result so far: 36868.5
The remainder is 305 after subtracting 2105 from 2410.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3050, and continue the process.

Moving on to step 10:
421 can be fit into 3050 7 times, resulting in a remainder of 103.
Record the quotient 7 as the next digit in the result. 
Result so far: 36868.57
Deduct 2947 from 3050 and we're left with 103.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1030, and continue the process.

Advancing to step 11:
When dividing 1030 by 421, we get 2 with a remainder of 188.
Record the quotient 2 as the next digit in the result. 
Result so far: 36868.572
Deduct 842 from 1030 and we're left with 188.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1880, and continue the process.

Let's proceed to step 12:
421 can be fit into 1880 4 times, resulting in a remainder of 196.
Put 4 as the next digit of the answer. 
Result so far: 36868.5724
If we subtract 1684 from 1880, we get 196.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1960, and continue the process.

Moving on to step 13:
1960 divided by 421 is 4 with a remainder of 276.
The next digit of our result is 4. 
Result so far: 36868.57244
Subtract 1684 from 1960 to get 276.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2760, and continue the process.

The quotient of the division is 36868.57244, and the remainder is 0.000276.