720 (number)
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| 720 | |
|---|---|
| Cardinal | Seven hundred [and] twenty |
| Ordinal | 720th (Seven hundred [and] twentieth) |
| Factorization |  |
| Divisor(s) | 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 |
| Roman numeral | DCCXX |
| Binary | 1011010000 |
| Hexadecimal | 2D0 |
Seven hundred twenty is the natural number following 719 and preceding 721.
It is 6! (6 factorial), a composite number with thirty divisors, more than any number below, making it a highly composite number. It is a Harshad number in every base from binary to decimal.
720 is expressible as the product of consecutive integers in two different ways: 720 = 2 × 3 × 4 × 5 × 6 = 8 × 9 × 10. [1] [2]
There are 49 solutions to the equation φ(x) = 720, more than any integer below it, making 720 a highly totient number.
720 is a 241-gonal number.
[edit] In other fields
720 is
- A common vertical display resolution for HDTV (see 720i and 720p).
- 720 and above is a good credit score.
- 720° is two full rotations; the term "720" is 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.
For the year AD, see 720.
[edit] References
- ^ Wells, David (1987). The Penguin Dictionary of Curious and Interesting Numbers. London: Penguin Books, 719.
- ^ Sequence A100933 at the On-Line_Encyclopedia_of_Integer_Sequences
