This website is a semi-functional mirror of the original Project Euler. More information is available on GitHub.
projecteuler.net

Smallest prime factor

Problem 521

Published on 21 June 2015 at 01:00 am [Server Time]

Let smpf(n) be the smallest prime factor of n.
smpf(91)=7 because 91=7×13 and smpf(45)=3 because 45=3×3×5.
Let S(n) be the sum of smpf(i) for 2 ≤ i ≤ n.
E.g. S(100)=1257.

Find S(1012) mod 109.


Answer not yet available
Go to back to Problems