4645 ÷ 1 = 4645 R0
Alright, let's work through the division of 4645 by 1 step by step.

Step 1:
1 goes into 4 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 4
Subtract 4 from 4 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 1

Step 2:
1 goes into 6 6 times with a remainder of 0.
Write down 6 as next digit of of the result. 
Result so far: 46
Subtract 6 from 6 to get 0.
Bring next digit (4) of the dividend behind the 0 and repeat the process: 4 / 1

Step 3:
1 goes into 4 4 times with a remainder of 0.
Write down 4 as next digit of of the result. 
Result so far: 464
Subtract 4 from 4 to get 0.
Bring next digit (5) of the dividend behind the 0 and repeat the process: 5 / 1

Step 4:
1 goes into 5 5 times with a remainder of 0.
Write down 5 as next digit of of the result. 
Result so far: 4645
Subtract 5 from 5 to get 0.

The final result is 4645 with a remainder of 0.