Band 311 (pronounced "three eleven") got their name from a police code after one of the band's former members was charged with indecent exposure. [Puckett]
The Federal Communications Commission (FCC) set aside the prime number 311, a telephone code now used in many U.S. Cities, for connection to police non-emergencies.
311 is the smallest number expressible as the sum of consecutive primes in four ways. [De Geest]
Apartment number 311 is the first door to be knocked on in the movie Ace Ventura: Pet Detective. [Shadyac]
Mickey Mantle's rookie card number 311 is prime. Note also that M+I+C+K+E+Y+M+A+N+T+L+E = 131 (A=1...Z=26), another prime which happens to contain the same digits as his rookie card number. [Rupinski]
The smallest three-digit prime that is the sum of three different three-digit primes. [Gallardo]
Timothy Leary claimed to have taken LSD a total of 311 times. [Coeburn]
The largest prime of the form |a^b - c^d|, where a, b, c and d are the first 4 primes. 311 = 7^3 - 2^5. Curiously, 311 = prime(2^6). [Post]
Sources of narrow spectrum radiation (UVB 311 nm) are considered to be the best for vitiligo and psoriasis treatment. [Homewood]
The Transportation Security Administration (TSA) has a "3-1-1" for carry-ons.
The smallest prime (emirp) that is the first of six consecutive primes that remain prime if you delete their first digit, i.e., 311, 313, 317, 331, 337, 347. [Loungrides]
(There are 11 curios for this number that have not yet been approved by an editor.)