#include<iostream>
#include<cassert>
#include<atcoder/modint>
using namespace std;
using mint=atcoder::modint998244353;
mint H(long a,int b)
{
	//H(a,b)=C(a+b-1,b)
	mint x=1,y=1;
	for(int i=1;i<=b;i++)x*=a+b-i,y*=i;
	return x/y;
}
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int T;cin>>T;
	for(;T--;)
	{
		long N,S;
		cin>>N>>S;
		mint ans=S;
		for(int p=2;p<=100;p++)if(N%p==0)
		{
			int e=0;
			while(N%p==0)N/=p,e++;
			const mint invp=mint(p).inv();
			mint now=0,pp=mint(p).pow(e);
			for(int f=e;f>=0;f--)
			{
				//pp=p.pow(e)*H(S-1,e-f)
				//=p.pow(e)*C(S-2+e-f,e-f)
				//=p.pow(e)*(S-2+e-f)...(S-2+1)/(e-f)!
				now+=pp;
				pp*=S-2+e-f+1;
				pp/=e-f+1;
				pp*=invp;
			}
			ans*=now;
		}
		cout<<ans.val()<<"\n";
	}
}