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Problem 429


Problem 429


Sum of squares of unitary divisors

A unitary divisor d of a number n is a divisor of n that has the property gcd(d, n/d) = 1.
The unitary divisors of 4! = 24 are 1, 3, 8 and 24.
The sum of their squares is 12 + 32 + 82 + 242 = 650.

Let S(n) represent the sum of the squares of the unitary divisors of n. Thus S(4!)=650.

Find S(100 000 000!) modulo 1 000 000 009.


元因数的平方和

n的元因数d指的是满足如下性质的n的因数:gcd(d, n/d) = 1。
4! = 24的元因数为1,3,8和24。
这些数的平方和是12 + 32 + 82 + 242 = 650。

记S(n)是n的元因子的平方和。因此S(4!)=650。

求S(100 000 000!) modulo 1 000 000 009。