is an office building situated in the US and it was built in 1991. Gambling and luck 777 is used on most slot machines in the United States to identify a jackpot. As it is considered a lucky number, banknotes with a serial number containing 777 tend to be valued by collectors and numismatists. The US Mint and the Bureau of Engraving and Printing sells uncirculated 777 $1 bills for this reason. References Integers Numerology