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。