#include <bits/stdc++.h>
#define _1 (__int128)1

using namespace std;
using ll = long long;

void FileIO (const string s) {
  freopen(string(s + ".in").c_str(), "r", stdin);
  freopen(string(s + ".out").c_str(), "w", stdout);
}

const int N = 2e6 + 10, mod = 998244353;

int n, inv[N], x[N], f[N], a, b, ans;
bool ip[N];

inline int C (int a, int b) {
  if (a < b) return 0;
  return 1ll * f[a] * x[b] % mod * x[a - b] % mod;
}

signed main () {
  ios::sync_with_stdio(0), cin.tie(0);
  // FileIO("");
  inv[1] = x[0] = f[0] = 1;
  for (int i = 2; i <= 2e6; i++)
    inv[i] = 1ll * (mod - mod / i) * inv[mod % i] % mod;
  for (int i = 1; i <= 2e6; i++)
    x[i] = 1ll * x[i - 1] * inv[i] % mod, f[i] = 1ll * f[i - 1] * i % mod;
  for (cin >> n; n--; ) {
    cin >> a >> b;
    for (int i = 2; i * i <= a; i++)
      while (a % i == 0)
        a /= i, ans++;
    if (a > 1) ans++;
    cout << C(ans - 1, b - 1) << '\n';
  }
  return 0;
}