#include<bits/stdc++.h>

using namespace std;

const int N = 4e6 + 5;
const int mod = 998244353;

int q, siz, p[N], vis[N];
vector<int> prime;
long long pl[N], inv[N], ipl[N];

void init(int inf){
  for(int i = 2; i <= inf; i++){
    if(!vis[i]){
      prime.push_back(i);
      vis[i] = i;
    }
    for(int v : prime){
      if(1ll * i * v > inf) break;
      vis[i * v] = v;
      if(i % v == 0) break;
    }
  }
  ipl[0] = ipl[1] = 1, inv[1] = 1, pl[0] = pl[1] = 1;
  for(int i = 2; i <= inf; i++){
    inv[i] = (mod - mod / i) * inv[mod % i] % mod;
    pl[i] = pl[i - 1] * i % mod;
    ipl[i] = ipl[i - 1] * inv[i] % mod;
  }
}

long long C(int n, int m){
  if(m > n) return 0;
  return pl[n] * ipl[m] % mod * ipl[n - m] % mod;
}

int main(){
  ios::sync_with_stdio(0), cin.tie(0);
  init(4000000);
  cin >> q;
  for(int i = 1, a, b; i <= q; i++){
    cin >> a >> b;
    for(; vis[a]; a /= vis[a]){
      siz++;
    }
    cout << C(siz - 1, b - 1) << '\n';
  }
  return 0;
}