21453 ÷ 4 = 5363 R1
Let's divide 21453 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 (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 (4) of the dividend behind the 1 and repeat the process: 14 / 4

Step 3:
4 goes into 14 3 times with a remainder of 2.
Write down 3 as next digit of of the result. 
Result so far: 53
Subtract 12 from 14 to get 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 4

Step 4:
4 goes into 25 6 times with a remainder of 1.
Write down 6 as next digit of of the result. 
Result so far: 536
Subtract 24 from 25 to get 1.
Bring next digit (3) of the dividend behind the 1 and repeat the process: 13 / 4

Step 5:
4 goes into 13 3 times with a remainder of 1.
Write down 3 as next digit of of the result. 
Result so far: 5363
Subtract 12 from 13 to get 1.

The final result is 5363 with a remainder of 1.