The bug is your line
sprintf() formats numeric values as character vectors and returns the character vector. The output of the sprintf() is not a number: it is a character vector. In your case it happens to be a character vector containing 15 characters, '10765655.982710', which is the vector ['1' '0' '7' '6' etc] .
You are then writing over your original numeric value with that character vector.
What was your intent in using sprintf() at that point in your code?