21687 ÷ 7 = 3098 R1
Let's divide 21687 by 7.

Step 1:
7 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 / 7

Step 2:
7 goes into 21 3 times with a remainder of 0.
Write down 3 as next digit of of the result. 
Result so far: 3
Subtract 21 from 21 to get 0.
Bring next digit (6) of the dividend behind the 0 and repeat the process: 6 / 7

Step 3:
7 goes into 6 0 times with a remainder of 6.
Write down 0 as next digit of of the result. 
Result so far: 30
Subtract 0 from 6 to get 6.
Bring next digit (8) of the dividend behind the 6 and repeat the process: 68 / 7

Step 4:
7 goes into 68 9 times with a remainder of 5.
Write down 9 as next digit of of the result. 
Result so far: 309
Subtract 63 from 68 to get 5.
Bring next digit (7) of the dividend behind the 5 and repeat the process: 57 / 7

Step 5:
7 goes into 57 8 times with a remainder of 1.
Write down 8 as next digit of of the result. 
Result so far: 3098
Subtract 56 from 57 to get 1.

The final result is 3098 with a remainder of 1.