Does delete free the space allocated by vectors in an array?

Suppose I create an array of vectors, and then I allocate memory for num_vectors many vectors. What happens when delete gets executed after making some push_back operations in random vector elements? I wonder if all the allocated memory (by new and push_back) gets freed.

int num_vectors = 123456;
std::vector<uint64_t>* arr_vecs;
arr_vecs = new std::vector<uint64_t>[num_vectors];

int random_ix;
int random_val = 999;

random_ix = 1;
arr_vecs[random_ix].push_back(random_val);

random_ix = 88;
arr_vecs[random_ix].push_back(random_val);

random_ix = 123;
arr_vecs[random_ix].push_back(random_val);

delete[] arr_vecs;

The question is not about good/bad practices in modern C++. I rather ask a specific question.

It seems like it gets freed, however I would like to have a better intuition about the expected behavior.