#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
int main () {
	int Q;
	cin >> Q;
	std::vector<mint> kai(Q * 20, 1), fkai(Q * 20, 1) ;
	for (int i = 1; i < Q * 20; i ++) kai[i] = kai[i-1] * i;
	fkai[Q*20-1] = kai[Q*20-1].inv();
	for (int i = Q*20-1; i; i --) {
		fkai[i-1] = fkai[i] * i;
	}
	int s = 0;
	auto comb = [&](int n, int r) -> mint{
		if (r < 0 || n < r) return 0;
		return kai[n] * fkai[r] * fkai[n - r];
	};
	while (Q--) {
		int a;
		cin >> a;
		int a2 = a;
		for (int i = 2; i * i <= a2; i ++) {
			if (a == 1) break;
			while (a % i == 0) {
				s ++;
				a /= i;
			}
		}
		s += (a > 1);
		int b;
		cin >> b;
		cout << comb(s - 1, b - 1).val() << endl;
	}
}