25591 ÷ 4 = 6397 R3
Let's divide 25591 by 4.

Step 1:
4 goes into 2 0 times with a remainder of 2.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 2 to get 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 4

Step 2:
4 goes into 25 6 times with a remainder of 1.
Write down 6 as next digit of of the result. 
Result so far: 6
Subtract 24 from 25 to get 1.
Bring next digit (5) of the dividend behind the 1 and repeat the process: 15 / 4

Step 3:
4 goes into 15 3 times with a remainder of 3.
Write down 3 as next digit of of the result. 
Result so far: 63
Subtract 12 from 15 to get 3.
Bring next digit (9) of the dividend behind the 3 and repeat the process: 39 / 4

Step 4:
4 goes into 39 9 times with a remainder of 3.
Write down 9 as next digit of of the result. 
Result so far: 639
Subtract 36 from 39 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 4

Step 5:
4 goes into 31 7 times with a remainder of 3.
Write down 7 as next digit of of the result. 
Result so far: 6397
Subtract 28 from 31 to get 3.

The final result is 6397 with a remainder of 3.