Researchers reveal a new prime number

Mathematicians have discovered a new prime number that is more that nine million digits long.It could help to solve the decades-old ‘Sierpinski problem.’
While it’s not the longest ever found, the existence of the new prime, 10223 × 2^31172165 + 1, now takes one of the six possible candidates for the lowest Sierpinski number out of the running.
Prime numbers are those divisible only by one and themselves, and the newly discovered figure is the seventh largest known to date.
For the last 50 years, mathematicians have been perplexed in their attempts to find the smallest Sierpinski number in existence.