We divide 539322 by 21
The aim is to understand the frequency of 21 in 539322.

Advancing to step 1:
21 can be fit into 5 0 times, resulting in a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 5 leaves us with 5.
Fetch the next digit (3) from the dividend, attach it to 5 and continue: 53 / 21

Step 2:
If we divide 53 by 21, we get 2 and a remainder of 11.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we subtract 42 from 53, we get 11.
Fetch the next digit (9) from the dividend, attach it to 11 and continue: 119 / 21

Moving on to step 3:
The number 21 fits into 119 5 times, leaving a remainder of 14.
Use 5 as the next digit of our solution. 
Result so far: 25.0
If we take 105 away from 119, we end up with 14.
Take the next digit (3) from the dividend and append it to 14, then repeat: 143 / 21

Advancing to step 4:
143 divided by 21 is 6 with a remainder of 17.
Use 6 as the next digit of our solution. 
Result so far: 256.0
If we take 126 away from 143, we end up with 17.
Include the next digit (2) from the dividend after 17, then repeat: 172 / 21

Going ahead to step 5:
21 can be fit into 172 8 times, resulting in a remainder of 4.
Use 8 as the next digit of our solution. 
Result so far: 2568.0
Subtract 168 from 172 to get 4.
Fetch the next digit (2) from the dividend, attach it to 4 and continue: 42 / 21

Moving on to step 6:
21 goes into 42 2 times with a remainder of 0.
The number 2 becomes the next digit in our result. 
Result so far: 25682.0
Subtracting 42 from 42 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.

Advancing to step 7:
0 divided by 21 is 0 with a remainder of 0.
Record the quotient 0 as the next digit in the result. 
Result so far: 25682.0
Deduct 0 from 0 and we're left 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 8:
21 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: 25682.0
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.

The final outcome is 25682.0, with a leftover of 0.0.