This number is a prime.
Groundhog Day in 2011 was a prime month, prime day, and prime year. If we concatenate the month, day, and year (i.e., 222011) it's also prime. Can you find the next future date in which these four things occur simultaneously? [Blanchette]
The smallest four digit prime assigned as an Australian postcode. It belongs to Kings Cross and Woollomolloo, New South Wales.
Solar researchers are predicting that the next solar maximum, expected to arrive in 2011, will be the strongest in a half-century.
The year terminating the smallest quadruplet of successive prime years that leaps over a millennium with increasing gaps 2n (n = 1, 2, 3): 1997, 1999, 2003, 2011. [Beedassy]
FIDE has announced that there will be a World Chess Championship cycle every two years beginning in 2011.
Former civil engineer Harold Camping of Oakland, who runs Family Radio, devised a mathematical system to interpret prophecies hidden within the Bible. His conclusion after crunching the numbers: The world will end May 21, 2011. Camping reasoned that the end should occur (5*10*17)^2 days after April 1, 33 A.D. See Prime News !
Two thousand "eleven" is the sum of 11 consecutive primes. Can you find them? [Post]
The horizontal reflection of 2011 (5011) on a calculator is also prime. [Beedassy]
The number of toothpicks in the sexagesimal stage of the toothpick sequence. [Pol]
The year 2011 marks the planet Neptune's first trip around the Sun since its discovery. [Landau]
Fitness guru and iconic actress Jane Fonda published "Prime Time" (her second memoir) in 2011.
The Cumberland darter (Etheostoma susanae) is a rare species of fish in the perch family endemic to Kentucky and Tennessee. In 2011 it was federally listed as an endangered species. [Estep]
The pop-punk band "Super Prime" fiercely stepped out into the Boston rock scene after forming in 2011 while attending Berklee College of Music.
World population rose to seven billion in 2011.
The first "Math Encounters" lecture was delivered in 2011.