31391 ÷ 4 = 7847 R3
Alright, let's work through the division of 31391 by 4 step by step.

Step 1:
4 goes into 3 0 times with a remainder of 3.
Write down 0 as next digit of of the result. 
Result so far: 0
Subtract 0 from 3 to get 3.
Bring next digit (1) of the dividend behind the 3 and repeat the process: 31 / 4

Step 2:
4 goes into 31 7 times with a remainder of 3.
Write down 7 as next digit of of the result. 
Result so far: 7
Subtract 28 from 31 to get 3.
Bring next digit (3) of the dividend behind the 3 and repeat the process: 33 / 4

Step 3:
4 goes into 33 8 times with a remainder of 1.
Write down 8 as next digit of of the result. 
Result so far: 78
Subtract 32 from 33 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 4

Step 4:
4 goes into 19 4 times with a remainder of 3.
Write down 4 as next digit of of the result. 
Result so far: 784
Subtract 16 from 19 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: 7847
Subtract 28 from 31 to get 3.

The final result is 7847 with a remainder of 3.