230 (number)

Summary

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

← 229 230 231 →
Cardinaltwo hundred thirty
Ordinal230th
(two hundred thirtieth)
Factorization2 × 5 × 23
Greek numeralΣΛ´
Roman numeralCCXXX
Binary111001102
Ternary221123
Senary10226
Octal3468
Duodecimal17212
HexadecimalE616

Additionally, 230 is:

  • a composite number, with its divisors being 2, 5, 10, 23, 46, and 115.
  • a sphenic number[1] because it is the product of 3 primes. It is also the first sphenic number to immediately precede another sphenic number.
  • palindromic and a repdigit in bases 22 (AA22), 45 (5545), 114 (22114), 229 (11229)
  • a Harshad number in bases 2, 6, 10, 12, 23 (and 16 other bases).
  • a happy number.[2]
  • a nontotient[3] since there is no integer with 230 coprimes below it.
  • the sum of the coprime counts for the first 27 integers.
  • the aliquot sum of both 454 and 52441.
  • part of the 41-aliquot tree.
  • the maximal number of pieces that can be obtained by cutting an annulus with 20 cuts.[4]

The aliquot sequence starting at 224 is: 224, 280, 440, 640, 890, 730, 602, 454, 230, 202, 104, 106, 56, 64, 63, 41, 1, 0.

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

Integers between 231 and 239 edit

231 edit

232 edit

233 edit

234 edit

235 edit

236 edit

237 edit

238 edit

239 edit

References edit

  1. ^ "Sloane's A007304 : Sphenic numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-09-05.
  2. ^ "Sloane's A007770 : Happy numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-09-05.
  3. ^ "Sloane's A005277 : Nontotients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-09-05.
  4. ^ Sloane, N. J. A. (ed.). "Sequence A000096 (a(n) = n*(n+3)/2)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.