Yeah this function is kinda weird so it does problems. Create your own pow function so it doesn't cause problems. Also the numbers you are using are very large so it will overflow

the pow function returns a "double" type.

You'd better use binary pow.

const long long MOD = 1e9 + 7;
long long binpow(long long n, long long p){
	long long res = 1;
	while(p) {
		if(p & 1) {
			res *= n;
			res %= MOD;
		}
		p >>= 1;
		n *= n;
		n %= MOD;
	}
	return res;
}