The largest known prime number (as of December 2019) is 282,589,933 − 1 (2 multiplied by itself 82,589,933 times minus 1), a number which has 24,862,048 digits when written in base 10.
A prime number is a number with no divisors other than 1 and itself.
The value of current largest prime number is:
148894445742041325547806458472397916603026273992795324185271289425213239361064475310309971132180337174752834401423587560
...
(24,861,808 digits omitted)
...
062107557947958297531595208807192693676521782184472526640076912114355308311969487633766457823695074037951210325217902591