21151 ÷ 4 = 5287 R3
Alright, let's work through the division of 21151 by 4 step by step.

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 (1) of the dividend behind the 2 and repeat the process: 21 / 4

Step 2:
4 goes into 21 5 times with a remainder of 1.
Write down 5 as next digit of of the result. 
Result so far: 5
Subtract 20 from 21 to get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 4

Step 3:
4 goes into 11 2 times with a remainder of 3.
Write down 2 as next digit of of the result. 
Result so far: 52
Subtract 8 from 11 to get 3.
Bring next digit (5) of the dividend behind the 3 and repeat the process: 35 / 4

Step 4:
4 goes into 35 8 times with a remainder of 3.
Write down 8 as next digit of of the result. 
Result so far: 528
Subtract 32 from 35 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: 5287
Subtract 28 from 31 to get 3.

The final result is 5287 with a remainder of 3.