B

#include <bits/stdc++.h>

using namespace std;

#define ll     long long
#define _test   int _TEST; cin>>_TEST; while(_TEST--)

int main()
{
    _test
    {
        int n;
        string s;
        cin>>n>>s;

        vector<int> cnt(26);
        for(auto e: s)
            cnt[e-'a']++;

        ll int ans = 1;
        int MOD = 1e9 + 7;

        for(auto e: cnt)
            (ans *= (e+1)) %= MOD;

        cout<<(ans-1)<<"\n";
    }
}