A page of the Numeropedia - the Special Encyclopedia of Numbers
... In Arithmetic, 1+1 = 2, in Computer Science, 1+1 = 0, but in Love, 1+1 = 1!
[Astronomy] The number of natural satellites (moons) of the planets Mercury and Venus.
[Biology] Cat is the only domestic animal not mentioned in the Holy Bible.
[Calendar] There is no year designated as year 0, for conventional calendar, (except for astronomy purposes): after the year 1 B.C. is the year 1 A.D. Legends: B.C. = Before Christ or, similarly, B.C.E. = Before Common Era. A.D. = Anno Domini (Year of Lord, in Latin) or, similarly, C.E. = Common Era.
[Geology] Antarctica is the only continent that has no country; many countries establish science stations here, but own no land.
[Geology] No country name (English) starting with letter X.
It is the only letter without starting a country name (English).
[Geology] The state of Delaware has no unit of National Park System, such as national parks, seashores, historic sites, battlefields, memorials and monuments.
[Geology] There is no major river in Saudi Arabia.
[Math.] There is no 7-digit prime number whose digits are consecutive (including digit 0).
There is no 9-digit prime number whose digits are consecutive (including digit 0).
[Math.] There is no 9-digit prime number that includes all 9 different digits from 1 to 9, in any order.
[Math.] There is no 10-digit prime number that includes all 10 different digits from 0 to 9, in any order.
[Math.] No prime number consisting of only repeated digits other than repeated digit 1’s. E.g., number 11 is a prime number.
[Science] Nobel prize has been never awarded posthumously.
[Sport] No country in Southern hemisphere hosted a winter Olympic Games.
The first city in Southern hemisphere hosted a summer Olympic Games is Melbourne.
[Tech.] There is no channel 1 on TV set dial knob and TV program, since in the 1940s, FCC assigned that channel to mobile services (e.g., two-way radios in taxicabs), but did not re-number the other channel assignments
[Trivia] There are two types of fools: those who trust everyone and those who trust no one.