#include <bits/stdc++.h>
#ifdef LOCAL
#define debug(...) 42
// #include "cp_debug.h"
#else
#define debug(...) 42
#endif
#define rep(i,a,b) for(int i = a; i < b; ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
using namespace std;
#define int long long

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;

template<typename T> void read(T &x){
    x = 0;char ch = getchar();ll f = 1;
    while(!isdigit(ch)){if(ch == '-')f*=-1;ch=getchar();}
    while(isdigit(ch)){x = x*10+ch-48;ch=getchar();}x*=f;
}
template<typename T, typename... Args> void read(T &first, Args& ... args) {
    read(first);
    read(args...);
}
template<typename T> void write(T x) {
    if(x > 9) write(x/10);
    putchar(x%10 + '0');
}

ll f(ll x) {
    ll ret = 0;
    for(int i = 1; i * i <= x; i++) {
        if(x % i == 0) {
            if(i*i==x) {
                ret++;
            } else {
                ret += 2;
            }
        }
    }
    return ret;
}

const ll INF = 2000000000000000000;
ll mul(ll x, ll y) {
    if(y == 0) return 0;
    if(x>=INF/y) return INF;
    return x*y;
}
ll qpow(ll x, ll y) {
    ll ans = 1;
    for(; y; y >>= 1, x = mul(x, x)) {
        if(y & 1) {
            ans = mul(ans, x);
        }
    }
    return ans;
}

void solve() {
    ll x;
    read(x);
    if(x == 1) {
        cout << 1 << '\n';
        return;
    }
    ll ans = -1;
    for(int i = 2; i <= 64; i++) {
        ll n_approx = pow(x, 1.0/i);
        for(ll n = max(1LL, n_approx - 3); n <= n_approx + 3; ++n) {
            if(qpow(n, i) == x) {
                if(f(n) == i) {
                    if(ans == -1 || ans > n) {
                        ans = n;
                    }
                }
                break;
            }
        }
    }
    cout << ans << '\n';
}

signed main() {
    int T; T=1;
    while(T--) solve();
    return 0;
}