YouTube's Google+ account,
"We never thought a video would be watched in numbers greater than a 32-bit integer (=2,147,483,647 views), but that was before we met PSY. 'Gangnam Style' has been viewed so many times we had to upgrade to a 64-bit integer (9,223,372,036,854,775,808)!"
-- From Slashdot, 3 December 2014
I think wrote about this once before. As of this morning, the 4 minute 13 second Gangnam Style video had been viewed 2,158,281,339 times. This adds up to 6,288,349 days, or 17,216 years total viewing time. Since this morning, it's been watched another 1,548,865 times, racking up another 12.4 years of viewing.