The US patent number is US 7198789 B2.
No, once a patent expires the invention is public domain and can never be patented again.
According to the article in Smart Money linked below, the patent continues through December 2016.
There is no US patent 555408021. There is also no US patent 55408021.
The number is 3359678
US Patent No. 1582
You will have to check with the US Patent Office
According to the link shown below, the United States Patent and Trademark Office lists the expiration date as October 23, 2012. http://www.fda.gov/OHRMS/DOCKETS/dailys/04/july04/071504/99e-1086-let00003-vol1.pdf
Humira is my name
It is US47114711UHP
That is the patent number for the first basketball. The person credited with inventing the basketball was G.L. Pierce.
Use this link to research US Patent Numbers: http://patft.uspto.gov/netahtml/PTO/srchnum.htm
United States Patent #51223123 does not exist. The highest US patent number as of 05-28-2010 is 7,725,947.