一本通1633：【例 3】Sumdiv

#include <cstdio>
#define LL long long

const int mod = 9901;

LL qmi(LL a, LL b) {
    LL res = 1, mul = a;

    while (b) {
        if (b & 1)
            res = res * mul % mod;

        mul = mul * mul % mod;
        b >>= 1;
    }

    return res;
}

int main() {
    LL a, b, ans = 1;
    scanf("%lld %lld", &a, &b);

    for (int i = 2, j; i <= a / i; i ++)
        if (a % i == 0) {
            j = 0;

            while (a % i == 0)
                a /= i, j ++;

            j *= b;
            ans *= (1 - qmi(i, j + 1)) * qmi(1 - i, mod - 2) % mod;
            ans %= mod;
        }

    if (a > 1)
        ans *= (1 - qmi(a, b + 1)) * qmi(1 - a, mod - 2) % mod;

    ans %= mod;
    printf("%lld", ans);
    return 0;
}