Definitely so but you should be the major contributor. No one should be the first author with insignificant contribution or forcing others to put the name as the first author.
I agree to Prof. Subir response. The first author should have contributed more. The order of authors is important. Commonly, third author or more do not contribute much. Some people insist to put as co-author if they do a small part of experiment. In some University departments or reseach labs, the head of the institution or lab forces to put his name in every paper irrespective of the contribution. In some cases, supervisors force their scholars to put their name as first author. Generally, first author is the major contributor than co-authors and carry more credits. I have also noticed single author papers from some scientists in my reseach field.