91997 ÷ 2 = 45998 R1
Alright, let's work through the division of 91997 by 2 step by step.

Step 1:
2 goes into 9 4 times with a remainder of 1.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 8 from 9 to get 1.
Bring next digit (1) of the dividend behind the 1 and repeat the process: 11 / 2

Step 2:
2 goes into 11 5 times with a remainder of 1.
Write down 5 as next digit of of the result. 
Result so far: 45
Subtract 10 from 11 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 2

Step 3:
2 goes into 19 9 times with a remainder of 1.
Write down 9 as next digit of of the result. 
Result so far: 459
Subtract 18 from 19 to get 1.
Bring next digit (9) of the dividend behind the 1 and repeat the process: 19 / 2

Step 4:
2 goes into 19 9 times with a remainder of 1.
Write down 9 as next digit of of the result. 
Result so far: 4599
Subtract 18 from 19 to get 1.
Bring next digit (7) of the dividend behind the 1 and repeat the process: 17 / 2

Step 5:
2 goes into 17 8 times with a remainder of 1.
Write down 8 as next digit of of the result. 
Result so far: 45998
Subtract 16 from 17 to get 1.

The final result is 45998 with a remainder of 1.