|Cardinal||nine hundred eleven|
(nine hundred eleventh)
911 (nine hundred [and] eleven) is the integer following 910 and preceding 912.
It is a prime number, a Sophie Germain prime and the sum of three consecutive primes (293 + 307 + 311). It is an Eisenstein prime with no imaginary part and real part of the form 3n − 1. Since 913 is a semiprime, 911 is a Chen prime. It is also a centered decagonal number.
911 is obtained by concatenating its product of digits and sum of digits.
- 9-1-1, a North American emergency telephone number
- 9/11, the September 11 attacks of 2001
- AD 911, a year
- Porsche 911, a sports car