What are the requirements for immigrating to Portugal?

Global Migration Online describes the situation of Portuguese immigrants as follows:

The principal applicant is over 18 years old;

No criminal record;

Purchase local real estate of more than 500,000 euros;

You can apply for permanent residence if you have invested for more than 5 years;

Residence requirements: 7 days in the first year, and every two years thereafter 14 days.