#include<bits/stdc++.h>
#define int long long
using namespace std;
const int mod=998244353;
const int N=1e6+10;
int n,p[N],k[N],m,s;
int Pow(int a,int b=mod-2){
    int s=1;
    while(b){
        if(b&1)s=s*a%mod;
        a=a*a%mod;b>>=1;
    }
    return s;
}
int C(int n,int m){
    if(n<m)return 0;
    if(m==0)return 1;
    int res=1;
    for(int i=(n-m+1);i<=n;++i)res=res*(i%mod)%mod;
    for(int i=1;i<=m;++i)res=res*Pow(i)%mod;
    return res;
}
void solve(){
    cin>>n>>s;m=0;
    int x=n;
    for(int i=2;i*i<=x;++i)if(x%i==0){
        p[++m]=i;while(x%i==0)++k[m],x/=i;
    }
    if(x!=1)p[++m]=x,k[m]=1;
    int ans=1;
    for(int i=1;i<=m;++i){
        int val=0;
        for(int j=0;j<=k[i];++j){
            val=(val+Pow(p[i],k[i]-j)%mod*C(s-2+j,j)%mod)%mod;
        }
        ans=ans*val%mod;
    }
    ans=ans*s%mod;
    cout<<ans<<'\n';
    return ;
}
signed main(){
    ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    int T;cin>>T;while(T--)solve();
    return 0;
}