#include<bits/stdc++.h>
#include<atcoder/all>

using namespace std;
using namespace atcoder;

#include<vector>

class CombinationMod
{
public :
    CombinationMod() = default;
    CombinationMod( int max_size, int mod ) : MAX_SIZE( max_size ),
                                              MOD( mod ),
                                              fac( max_size, 1 ),
                                              finv( max_size, 1 ),
                                              inv( max_size, 1 )
    {
        for ( int i = 2; i < MAX_SIZE; i++ )
        {
            fac[i] = fac[i - 1] * i % MOD;
            inv[i] = MOD - inv[ MOD % i] * ( MOD / i ) % MOD;
            finv[i] = finv[i - 1] * inv[i] % MOD;
        }
    }

    long long calculateCombination( int n, int k )
    {
        if( n < k ) return 0;
        if( n < 0 || k < 0 ) return 0;

        return fac[n] * ( finv[k] * finv[n - k] % MOD ) % MOD;
    }

    int getMaxSize( void ) { return MAX_SIZE; }
    int getMod( void ) { return MOD; }

private :
    int MAX_SIZE, MOD;
    std::vector<long long> fac;
    std::vector<long long> finv;
    std::vector<long long> inv;
};

int main( void )
{
    CombinationMod com( 1800000, 998244353 );

    int Q;
    cin >> Q;

    int cur = 0;
    int A, B;
    while( Q-- > 0 )
    {
        cin >> A >> B;
        for( int i = 2; i * i <= A; i++ )
        {
            while( A % i == 0 )
            {
                A /= i;
                cur++;
            }
        }
        if( A != 1 ) cur++;

        if( cur < B )
        {
            cout << 0 << endl;
        }
        else
        {
            cout << com.calculateCombination( cur - 1, B - 1 ) << endl;
        }
    }
    

    return 0;
}