720 (number) explained

Number:	720
Divisor:	1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, 80, 90, 120, 144, 180, 240, 360, 720

720 (seven hundred [and] twenty) is the natural number following 719 and preceding 721.

In mathematics

720 is:

• 6! (6 factorial).
• a composite number with 30 divisors, more than any number below, making it a highly composite number.
• a highly abundant number.
• a Harshad number in every base from binary to decimal.
• the smallest number to be palindromic in 16 bases.
• a 241-gonal number.

720 is expressible as the product of consecutive integers in two different ways: and .^[1]

There are 49 solutions to the equation, more than any integer below it, making 720 a highly totient number.^[2]

In other fields

720 is:

• A common vertical display resolution for HDTV (see 720p).
• 720° is two full rotations; the term "720" refers to a skateboarding trick.
• 720° is also the name of a skateboarding video game.
• 720 is a dual area code in the Denver Metro Area along with 303.
• 720° is the sum of all the defects of any polyhedron.
• 720 is a short form of saying Boeing 720, an airliner which is no longer in service.

For the year AD, see 720.

References

1. Book: Wells, David. David Wells. The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books. 1987. London. 719.
2. Highly totient numbers: each number k on this list has more solutions to the equation phi(x) = k than any preceding k.