Puzzle Zero: Consecutive Sums Most integers can be expressed as the sum of two or more consecutive integers. For example, 72 = 23 + 24 + 25, 25 = 3 + 4 + 5 + 6 + 7, and 209 = 104 + 105. However, not all integers can be expressed in this fashion. In particular, there is exactly one number between 1,000,000 - 2,000,000 that cannot be expressed this way. What number is this?