I am working on a C++ program and I notice that

int main() {
    printf("%bn", (uint64_t(1) << 37) - 1);
    return 0;
}

returns

11111111111111111111111111111111

Exactly 32 bits. The same happens if I print the largest uint64_t. What I mean is that the following code:

int main() {
    printf("%bn", UINT64_MAX);
    return 0;
}

returns

11111111111111111111111111111111

Exactly 32 bits again. I do not know what to do, why is this happening?

Thanks in advance.