210 is the natural number following 209 and preceding 211.
| Cardinal | Two hundred [and] ten |
| Ordinal | 210th Two hundred [and] tenth |
| Factorization |  |
| Divisors | 2, 3, 5, 6, 7, 10, 14, 15, 21, 30, 35, 42, 70, 105 |
| Roman numeral | CCX |
| Binary | 11010010 |
| Duodecimal | 156 |
| Hexadecimal | D2 |
In mathematics
210 is a composite number, an abundant number, and the product of the first four prime numbers (2, 3, 5, and 7), and thus a primorial. It is also the sum of eight consecutive prime numbers (13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 = 210).[1]
It is a triangular number (following 190 and preceding 231), a pentagonal number (following 176 and preceding 247), and the second smallest to be both triangular and pentagonal (the third is 40755).[1]
It is also a pentatope number, a pronic number, a Harshad number, and an untouchable number. 210 is also the first 71-gonal number, preceding 418.[1]
211–219
Two hundred [and] eleven has its own article.
Two hundred [and] twelve has its own article.
Two hundred [and] thirteen has its own article.
Two hundred [and] fourteen has its own article.
Two hundred [and] fifteen 215 = 5·43. Form DD 215 is for corrections to form DD 214. Repdigit in base 6 (555).
The area code for a large portion of the Philadelphia Metropolitan Area.
Two hundred [and] sixteen has its own article.
216 is the magic product for the smallest possible multiplicative magic square. [1]
216 and 12,960,000 are Plato's numbers. [2]
Two hundred [and] seventeen 217 = 7·31, Blum integer, centered hexagonal number
The area code covering most of central Illinois.
Two hundred [and] eighteen 218 = 2·109, Mertens function(218) = 3 a record high that stands until 219, nontotient, noncototient
§ 218 is the section of the German StGB legal code that relates to abortion.
As of 2008, 218 is the number of votes required in the US House of Representatives to achieve a majority.[2]
Two hundred [and] nineteen 219 = 3·73, Mertens function(219) = 4 a record high that stands until 221, 219 is a repdigit in base 8 (333).
There are 219 space groups in 3 dimensions, analogous to the 17 wallpaper groups in 2 dimensions. 11 of them have 2 forms each, with left-hand screw and right-hand screw (see screw axis), so from this perspective there are 230 space groups.
References
- ^ a b c Wells, D. (1987). The Penguin Dictionary of Curious and Interesting Numbers (p. 143). London: Penguin Group.
- ^ http://news.bbc.co.uk/2/hi/americas/7652112.stm
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