Number 42

The angle in degrees for which a rainbow appears, called the critical angle.

In the Hitchhiker's Guide to the Galaxy by Douglas Adams, Deep Thought gives 42 as the Ultimate Answer to the Ultimate Question of Life, The Universe, and Everything.

The number of spots on a pair of standard six-sided dice.

Number 2

Two is the lowest channel of television in the United States, Canada, Argentina and Mexico on which the signals are broadcast.

In Jewish law, the testimony of two witnesses are required to verify and validate events, such as marriage, divorce, and a crime that warrants capital punishment.

The glyph we use today in the Western world to represent the number traces its roots back to the Brahmin Indians, who wrote it as two horizontal lines (it is still written that way in Chinese and Japanese).

Number 35

If you're married for 35 years, it is the coral wedding anniversary.

The 35 mm film is the basic film gauge most commonly used for both analog photography and motion pictures.

Famous classical composer Mozart died at the age of 35.

Number 21

In badminton, 21 points are required to win a game.

It is in the title of the TV show 21 Jump Street, starring Johnny Depp.

The 21 Club is a top restaurant in New York City.

Number 17

The number to call the police in France.

In Nordic countries the seventeenth day of the year is considered the heart and/or the back of winter.

Seventeen is a magazine title.

Number 4

There are four natural elements: fire, air, water, earth; four seasons: spring, summer, autumn and winter; and there are four cardinal directions: north, south, east and west.

In Astrology, Cancer is the fourth astrological sign of the Zodiac.

Four, the fourth album by rock jam band Blues Traveler