0%

# Problem 642

## Sum of largest prime factors

Let $f(n)$ be the largest prime factor of $n$ and $F(n)=\sum_{i=2}^nf(i)$.
For example $F(10)=32$, $F(100)=1915$ and $F(10000)=10118280$.

Find $F(201820182018)$. Give your answer modulus $10^9$.