{"problem":{"name":"Sum of Divisors","description":{"content":"For a positive integer $X$, let $f(X)$ be the number of positive divisors of $X$. Given a positive integer $N$, find $\\sum_{K=1}^N K\\times f(K)$.","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":3000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc172_d"},"statements":[{"statement_type":"Markdown","content":"For a positive integer $X$, let $f(X)$ be the number of positive divisors of $X$.\nGiven a positive integer $N$, find $\\sum_{K=1}^N K\\times f(K)$.\n\n## Constraints\n\n*   $1 \\leq N \\leq 10^7$\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc172_d","tags":[],"sample_group":[["4","23\n\nWe have $f(1)=1$, $f(2)=2$, $f(3)=2$, and $f(4)=3$, so the answer is $1\\times 1 + 2\\times 2 + 3\\times 2 + 4\\times 3 =23$."],["100","26879"],["10000000","838627288460105\n\nWatch out for overflows."]],"created_at":"2026-03-03 11:01:14"}}