Why is the human genome project called a mega project?

Human genome project was aimed to determine the complete base sequence of human DNA.

Human genome project is called a mega project because
(i) Its aim was to determine the nucleotide sequence of complete human genome which was a task of enormous magnitude.
(ii) a total of $3\times {10}^9$ base pairs were to be sequenced and the cost was about 9 billion US dollars.
(iii) it required bioinformatics data base techniques and other contemporary devices for the analysis, storage and retrieval of information.
(iv) many countries worked jointly to complete this timed project.