We look at the division of 21174867 by 591 
The aim is to understand the frequency of 591 in 21174867.

Moving on to step 1:
When dividing 2 by 591, we get 0 with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 591

Let's proceed to step 2:
21 divided by 591 is 0 with a remainder of 21.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Fetch the next digit (1) from the dividend, attach it to 21 and continue: 211 / 591

Let's proceed to step 3:
211 divided by 591 is 0 with a remainder of 211.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 211 and we're left with 211.
Fetch the next digit (7) from the dividend, attach it to 211 and continue: 2117 / 591

Moving on to step 4:
2117 divided by 591 is 3 with a remainder of 344.
Record the quotient 3 as the next digit in the result. 
Result so far: 3.0
If we subtract 1773 from 2117, we get 344.
Include the next digit (4) from the dividend after 344, then repeat: 3444 / 591

Let's proceed to step 5:
3444 divided by 591 is 5 with a remainder of 489.
Put 5 as the next digit of the answer. 
Result so far: 35.0
Subtract 2955 from 3444 to get 489.
Grab the next digit (8) from the dividend, add it to 489, then carry on: 4898 / 591

Moving on to step 6:
When dividing 4898 by 591, we get 8 with a remainder of 170.
The next digit of our result is 8. 
Result so far: 358.0
The remainder is 170 after subtracting 4728 from 4898.
Include the next digit (6) from the dividend after 170, then repeat: 1706 / 591

Step 7:
If we divide 1706 by 591, we get 2 and a remainder of 524.
Record the quotient 2 as the next digit in the result. 
Result so far: 3582.0
Subtracting 1182 from 1706 leaves us with 524.
Bring next digit (7) of the dividend behind the 524 and repeat the process: 5247 / 591

On to step 8:
591 goes into 5247 8 times with a remainder of 519.
Use 8 as the next digit of our solution. 
Result so far: 35828.0
If we take 4728 away from 5247, we end up with 519.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5190, and continue the process.

On to step 9:
When dividing 5190 by 591, we get 8 with a remainder of 462.
Record the quotient 8 as the next digit in the result. 
Result so far: 35828.8
If we subtract 4728 from 5190, we get 462.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4620, and continue the process.

On to step 10:
591 goes into 4620 7 times with a remainder of 483.
Put 7 as the next digit of the answer. 
Result so far: 35828.87
Deduct 4137 from 4620 and we're left with 483.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4830, and continue the process.

Advancing to step 11:
If we divide 4830 by 591, we get 8 and a remainder of 102.
Use 8 as the next digit of our solution. 
Result so far: 35828.878
If we take 4728 away from 4830, we end up with 102.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1020, and continue the process.

Advancing to step 12:
591 can be fit into 1020 1 times, resulting in a remainder of 429.
The number 1 becomes the next digit in our result. 
Result so far: 35828.8781
Deduct 591 from 1020 and we're left with 429.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4290, and continue the process.

Going ahead to step 13:
591 can be fit into 4290 7 times, resulting in a remainder of 153.
Put 7 as the next digit of the answer. 
Result so far: 35828.87817
The remainder is 153 after subtracting 4137 from 4290.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1530, and continue the process.

Advancing to step 14:
1530 divided by 591 is 2 with a remainder of 348.
The number 2 becomes the next digit in our result. 
Result so far: 35828.878172
Deduct 1182 from 1530 and we're left with 348.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3480, and continue the process.

Moving on to step 15:
The number 591 fits into 3480 5 times, leaving a remainder of 525.
Write down 5 as next digit of the result. 
Result so far: 35828.8781725
Deduct 2955 from 3480 and we're left with 525.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5250, and continue the process.

Step 16:
If we divide 5250 by 591, we get 8 and a remainder of 522.
Write down 8 as next digit of the result. 
Result so far: 35828.87817258
Deduct 4728 from 5250 and we're left with 522.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5220, and continue the process.

After the division, we end up with 35828.87817258 and a remainder of 5.22e-07.