1011.

Eleven is the natural number following ten and preceding twelve. It is also the smallest positive integer requiring three syllables in English. It's the fifth smallest prime number. It's the smallest two-digit prime number. Eleven is the fourth Sophie Germain prime, the third safe prime, the fourth Lucas prime, the first repunit prime.

Eleven is the atomic number for sodium. It is the number of spacetime dimensions in M-theory. The eleventh moon of Jupiter is Himalia.

A complete eleventh chord has almost every note of a scale. There are eleven thumb keys on a bassoon. While most amplifiers go only to ten, the band Spinal Tap's amplifiers go up to eleven. In fact, in 2002, the phrase "turning it up to eleven" entered the Shorter Oxford English Dictionary, with the definition "up to maximum volume."

World War I ended with an Armistice on November 11, 1918, which went into effect at 11:00 a.m. -- the eleventh hour of the eleventh day of the eleventh month of the year. Armistice Day is still observed on November 11 of each year, although it is now called Veteran's Day in the United States and Remembrance Day in the Commonwealth of Nations and parts of Europe.

Eleven is the first number that can't be counted on a human's ten fingers.

In tarot, the eleventh card is Justice. In Basque, the word hamaika ("eleven") has the double meaning of "infinite." In numerology, eleven is the first of the Master Numbers.

The number eleven is mysterious and beautiful.

Happy 11th!