#include <cstdio>
#include <algorithm>
#define ll long long int
using namespace std;
const int MAX = 1e7+10;
int t, c;
int ans[MAX];
int prime[MAX], pcount;
bool vis[MAX];
ll d[MAX], f[MAX];
void eular() {
    for (int i = 1; i <= MAX; i++) ans[i] = MAX;
    ans[1] = 1;
    for (int i = 2; i < MAX; i++) {
        if (!vis[i]) {
            vis[i] = 1;
            prime[pcount++] = i;
            d[i] = f[i] = i + 1;
            if (ans[i + 1] > i) ans[i + 1] = i;
        }
        for (int j = 0; j < pcount && (ll)prime[j] * i < MAX; j++) {
            vis[prime[j] * i] = 1;
            if (i % prime[j] == 0) {
                f[prime[j] * i] = f[i] * prime[j] + 1;
                d[prime[j] * i] = d[i] / f[i] * f[prime[j] * i];
            } else {
                f[prime[j] * i] = f[prime[j]];
                d[prime[j] * i] = d[i] * f[prime[j] * i];
            }
            if (d[prime[j] * i] < MAX && ans[d[prime[j] * i]] > prime[j] * i) ans[d[prime[j] * i]] = prime[j] * i;
            if (i % prime[j] == 0) break;
        }
    }
}
int main() {
    eular();
    scanf("%d", &t);
    while(t--) {
        scanf("%d", &c);
        if (ans[c] != MAX) printf("%d\n", ans[c]);
        else printf("-1\n");
    }
    return 0;
}