Nineteen (19) is a positive integer one more than 18 and one less than 20.


19 is the eighth prime number, between 17 (which it forms a twin prime pair with), and 23.

19 is a Mersenne exponent producing the prime 524287.

In googology Edit

In Greek-based number-naming systems, is associated with prefix "enneadeka-", and with prefix "novemdec-" in Latin systems.

Sbiis Saibian calls the number enneaxis, and it's equal to 10+9 using the addition.

Its Roman numeral (XIX) is used in Fibonaxix.