146 (number)

Last updated
146 magnetic balls, arranged to show that 146 is an octahedral number Octahedral number.jpg
146 magnetic balls, arranged to show that 146 is an octahedral number
145 146 147
Cardinal one hundred forty-six
Ordinal 146th
(one hundred forty-sixth)
Factorization 2 × 73
Divisors 1, 2, 73, 146
Greek numeral ΡΜϚ´
Roman numeral CXLVI, cxlvi
Binary 100100102
Ternary 121023
Senary 4026
Octal 2228
Duodecimal 10212
Hexadecimal 9216

146 (one hundred [and] forty-six) is the natural number following 145 and preceding 147.

Contents

In mathematics

146 is an octahedral number, the number of spheres that can be packed into in a regular octahedron with six spheres along each edge. [1] For an octahedron with seven spheres along each edge, the number of spheres on the surface of the octahedron is again 146. [2] It is also possible to arrange 146 disks in the plane into an irregular octagon with six disks on each side, making 146 an octo number. [3]

There is no integer with exactly 146 coprimes less than it, so 146 is a nontotient. It is also never the difference between an integer and the total of coprimes below it, so it is a noncototient. [4] And it is not the sum of proper divisors of any number, making it an untouchable number. [5]

There are 146 connected partially ordered sets with four labeled elements. [6] 146 is also a repdigit in base 8 (222).

See also

References

  1. Sloane, N. J. A. (ed.). "SequenceA005900(Octahedral numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  2. Sloane, N. J. A. (ed.). "SequenceA005899(Number of points on surface of octahedron)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  3. Sloane, N. J. A. (ed.). "SequenceA079273(Octo numbers)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  4. Sloane, N. J. A. (ed.). "SequenceA058763(Integers which are neither totient nor cototient)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  5. Sloane, N. J. A. (ed.). "SequenceA005114(Untouchable numbers, also called nonaliquot numbers: impossible values for the sum of aliquot parts function)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
  6. Sloane, N. J. A. (ed.). "SequenceA001927(Number of connected partially ordered sets with n labeled points)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.