If you thought the world's longest word that took over three hours to say was a little lengthy, wait till you hear about this latest prime number that a US mathematician has managed to crunch up - It is, drum roll please . . . A massive 17,425,170 digits long! To put it in perspective, if you decided to hand write it at a pace of one digit per second nonstop for 12 hours, it would take more than a year. Want to print it? Get ready to use at least 5,000 - 6,000 sheets, depending on the size of the paper and font!