Delhi (/ˈdɛli/, Hindustani pronunciation: [d̪ɪlliː] Dilli), (Urdu: دلی, Hindi: दिल्ली) officially the National Capital Territory of Delhi or NCT, is a city and a union territory of India. It is bordered by Haryana on three sides and by Uttar Pradesh to the east. The NCT covers an area of 1,484 square kilometres (573 sq mi). According to 2011 census, Delhi's city proper population was over 11 million, the second highest in India after Mumbai, while the whole NCT's population was about 16.8 million. Delhi's urban area is now considered to extend beyond the NCT boundary to include an estimated population of over 26 million people making it the world's second largest urban area. As of 2016[update] recent estimates of the metro economy of its urban area have ranked Delhi either the top or second most productive metro area of India. Delhi is the second wealthiest city after Mumbai in India, with a total wealth of $450 billion and home to 18 billionaires and 23,000 millionaires.