Formula to convert number to comma separated values
=TEXT(C2,REPT("0\,",LEN(C2)-1)&0)
The Excel TEXT() function is used to convert a number into text.
The function takes two parameters
1) the "value" (or number)
2) the "format" text
Therefore, in the above formula the first parameter is the cell that has number and the second paramter has another function called "REPT()", which will repeat the "commas" after each number.
Here's another example of TEXT() function.
Let us assume I have number 14875 and I want to change the value in "0.00" format. The formula will be...
=TEXT("14875","0.00")
Or
=TEXT(A2,"0.00")