Inauguration Day by the numbers

800,000 -- The approximate number of people who stood on the National Mall to watch President Barack Obama be sworn in.

1.1 million -- Inauguration related tweets during the ceremony. In 2009, the number was just 82,000 tweets.

42 -- The average temperature during the inauguration ceremony

1985 -- The last time Jan. 20, the date a president's term must begin, fell on a weekend after theelection.. Ronald Reagan was also sworn in privately in 1985, and had a ceremonial service the next day publicly.

2,000 -- The number of police officers from around the country who were brought in as extra reinforcement to Washington, D.C. this weekend to help with inauguration security

2,095 -- The number of words in President Obama's inaugural speech. The average speech had 2,357, so Obama's was short in comparison.