Your code looks almost right, except for 3 things:
1) To iterate 7830457 times, the loop condition should be "i < 7830457", not "i <= 7830457".
2) I suspect that the constant 10000000000 may be treated as an int by default, instead of a long long, and get truncated. Try writing the constant as 10000000000LL or 10000000000LLU instead; that should tell the compiler that the constant is long long or unsigned long long, resp. Do this everywhere you use this number.
3) After "number++;", you need to reduce number mod 10000000000 again, just in case it happened to be exactly 10000000000.
Edit: Oh, and 4) The printf() specifiers for long long and unsigned long long should be %ll and %llu, respectively. %d is for int. I think this is correct, based on some googling, I've never actually used them.