We divide 66360122 by 621
The aim is to understand the frequency of 621 in 66360122.

Step 1:
621 can be fit into 6 0 times, resulting in a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 6 and we're left with 6.
Bring next digit (6) of the dividend behind the 6 and repeat the process: 66 / 621

Advancing to step 2:
If we divide 66 by 621, we get 0 and a remainder of 66.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 66, we get 66.
Bring next digit (3) of the dividend behind the 66 and repeat the process: 663 / 621

Step 3:
If we divide 663 by 621, we get 1 and a remainder of 42.
Use 1 as the next digit of our solution. 
Result so far: 1.0
Subtracting 621 from 663 leaves us with 42.
Bring next digit (6) of the dividend behind the 42 and repeat the process: 426 / 621

Step 4:
426 divided by 621 is 0 with a remainder of 426.
Record the quotient 0 as the next digit in the result. 
Result so far: 10.0
Deduct 0 from 426 and we're left with 426.
Fetch the next digit (0) from the dividend, attach it to 426 and continue: 4260 / 621

Moving on to step 5:
The number 621 fits into 4260 6 times, leaving a remainder of 534.
The next digit of our result is 6. 
Result so far: 106.0
If we take 3726 away from 4260, we end up with 534.
Bring next digit (1) of the dividend behind the 534 and repeat the process: 5341 / 621

Moving on to step 6:
If we divide 5341 by 621, we get 8 and a remainder of 373.
The next digit of our result is 8. 
Result so far: 1068.0
Subtract 4968 from 5341 to get 373.
Bring next digit (2) of the dividend behind the 373 and repeat the process: 3732 / 621

Going ahead to step 7:
The number 621 fits into 3732 6 times, leaving a remainder of 6.
Record the quotient 6 as the next digit in the result. 
Result so far: 10686.0
The remainder is 6 after subtracting 3726 from 3732.
Fetch the next digit (2) from the dividend, attach it to 6 and continue: 62 / 621

On to step 8:
62 divided by 621 is 0 with a remainder of 62.
The number 0 becomes the next digit in our result. 
Result so far: 106860.0
If we subtract 0 from 62, we get 62.
Since there are no more digits in the dividend, we add a zero to the remainder making it 620, and continue the process.

Advancing to step 9:
621 goes into 620 0 times with a remainder of 620.
Put 0 as the next digit of the answer. 
Result so far: 106860.0
Deduct 0 from 620 and we're left with 620.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6200, and continue the process.

Let's proceed to step 10:
6200 divided by 621 is 9 with a remainder of 611.
Use 9 as the next digit of our solution. 
Result so far: 106860.09
If we subtract 5589 from 6200, we get 611.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6110, and continue the process.

Step 11:
621 can be fit into 6110 9 times, resulting in a remainder of 521.
Put 9 as the next digit of the answer. 
Result so far: 106860.099
Subtract 5589 from 6110 to get 521.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5210, and continue the process.

After the division, we end up with 106860.099 and a remainder of 0.0521.