题目描述
Problem Description
Define a multiplicative function \( f(x) \), where \( f(p^k) = p^k(p^k - 1) \) (with \( p \) being a prime number). Calculate
\[ \sum_{i = 1}^n f(i) \]
modulo \( 10^9 + 7 \).
Input Format
A single line containing an integer \( n \).
Output Format
A single integer representing the answer.
Sample Input and Output
Sample Input #1
10
Sample Output #1
263
Sample Input #2
1000000000
Sample Output #2
710164413
Notes
\( f(1) = 1 \), \( f(2) = 2 \), \( f(3) = 6 \), \( f(4) = 12 \), \( f(5) = 20 \);
\( f(6) = 12 \), \( f(7) = 42 \), \( f(8) = 56 \), \( f(9) = 72 \), \( f(10) = 40 \).
For 30% of the data, it is guaranteed that \( 1 \le n \le 10^6 \).
For 100% of the data, it is guaranteed that \( 1 \le n \le 10^{10} \).
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
10
样例输出
263