230 (number)

230 ("two hundred [and] thirty") is the natural number following 229 and preceding 231.

In mathematics

It is a composite number, with its divisors being 2, 5, 10, 23, 46, and 115. Its factorisation makes it a sphenic number. There is no integer with 230 coprimes below it, thus 230 is a nontotient. However, the sum of the coprime counts for the first 27 integers is 230.

There are 230 unique space groups describing all possible crystal symmetries.

In base 10, being divisible by the sum of its digits, 230 is a Harshad number.

In other fields

230 is:
* A common voltage in the European Union.
* The year A.D. 230 or 230 BC.

230 - 239

Two hundred thirty-one 231 = 3·7·11, sphenic number, triangular number, hexagonal number, octahedral number, Mertens function returns 0.

Two hundred thirty-one is the exact number of cubic inches in a U.S. liquid gallon.----Two hundred thirty-two 232 = 2³·29, decagonal number, Mertens function returns 0, noncototient, refactorable number----Two hundred thirty-three 233 prime, Fibonacci number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, Markov number, self number, teenage slang for "best friends forever"----Two hundred thirty-four 234 = 2·3²·13, Harshad number, nontotient----Two hundred thirty-five 235 = 5·47, sum of three consecutive primes (73 + 79 + 83), Mertens function returns 0, Smarandache-Wellin number, centered triangular number

U-235 is the fissile isotope of uranium used in the first atomic bombs.----Two hundred thirty-six 236 = 2²·59, Mertens function returns 0, nontotient----Two hundred thirty-seven 237 = 3·79, Blum integer. Room 237 plays a significant role in the Stanley Kubrick film "The Shining".----Two hundred and thirty-eight 238 = 2·7·17, sphenic number, sum of the first thirteen primes, Mertens function returns 0, untouchable number.

Two hundred thirty eight is the number of Interstate 238, an interstate highway that does not obey traditional interstate numbering rules, there being no Interstate 38. It is part of the Interstate 80 family, and connects Interstate 580 with Interstate 880.

U-238 is the non-fissile isotope of uranium that is the heaviest isotope of any material available through extraction from minerals.----
Two hundred thirty-nine has its own article.