#include <bits/stdc++.h>
#include <atcoder/all>
using mint = atcoder::static_modint<998244353>;
//using mint = atcoder::static_modint<1000000007>;
using namespace std;
using namespace atcoder;
using ld = long double;
using ll = long long;
#define mp(a,b) make_pair(a,b)
#define rep(i,s,n) for(int i=s; i<n; i++)
const vector<int> dx{1,0,-1,0},dy{0,1,0,-1};

const int m=5000000;
vector<mint> factorial(m,1),invfactorial(m,1);
mint combi(int n,int r){
    if(0<=r && r<=n)return factorial[n]*invfactorial[r]*invfactorial[n-r];
    else return 0;
}
int main(){
    int Q;
    cin >> Q;
    rep(i,1,m)factorial[i]=factorial[i-1]*i,invfactorial[i]=factorial[i].inv();
    int cnt=0;
    vector<mint> ans;
    rep(q,0,Q){
        int a,b;
        cin >> a>> b;
        for(int i=2; i*i<=a; i++)if(a%i==0){
            while(a%i==0)cnt++,a/=i;
        }
        if(a>1)cnt++;
        //cout << cnt << "\n";
        ans.push_back(combi(cnt-1,b-1));
    }
    for(auto x:ans)cout << x.val() << "\n";
}