An 8-digit number represents a quantity between 10,000,000 and 99,999,999. In terms of millions and billions, an 8-digit number is in the millions range, specifically between 10 and 100 million. To be in the billions range, a number must have 10 digits, or be greater than or equal to 1,000,000,000. Therefore, an 8-digit number is not a billion, but is a million.