------
## 最终结论
```python
def count_consecutive_sum(N):
    count = 0
    k = 1  # Start from 1 since a single number is also a valid consecutive sum
    
    while k * (k - 1) // 2 < N:
        if (N - k * (k - 1) // 2) % k == 0:
            count += 1
        k += 1
    
    return count

# Example usage:
print(count_consecutive_sum(5))   # Output: 2
print(count_consecutive_sum(9))   # Output: 3
print(count_consecutive_sum(15))  # Output: 4
```