23121 ÷ 4 = 5780 R1
Let's divide 23121 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 (3) of the dividend behind the 2 and repeat the process: 23 / 4

Step 2:
4 goes into 23 5 times with a remainder of 3.
Write down 5 as next digit of of the result. 
Result so far: 5
Subtract 20 from 23 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 4

Step 3:
4 goes into 31 7 times with a remainder of 3.
Write down 7 as next digit of of the result. 
Result so far: 57
Subtract 28 from 31 to get 3.
Bring next digit (2) of the dividend behind the 3 and repeat the process: 32 / 4

Step 4:
4 goes into 32 8 times with a remainder of 0.
Write down 8 as next digit of of the result. 
Result so far: 578
Subtract 32 from 32 to get 0.
Bring next digit (1) of the dividend behind the 0 and repeat the process: 1 / 4

Step 5:
4 goes into 1 0 times with a remainder of 1.
Write down 0 as next digit of of the result. 
Result so far: 5780
Subtract 0 from 1 to get 1.

The final result is 5780 with a remainder of 1.