380
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 840
- Proper Divisor Sum (Aliquot Sum)
- 460
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 144
- Möbius Function
- 0
- Radical
- 190
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- yes
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 107
- Smith Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Names
- German
- dreihundertachtzig· ordinal: dreihundertachtzigste
- English
- three hundred eighty· ordinal: three hundred eightieth
- Spanish
- trescientos ochenta· ordinal: 380º
- French
- trois cent quatre-vingts· ordinal: trois cent quatre-vingtsième
- Italian
- trecentoottanta· ordinal: 380º
- Latin
- trecenti octoginta· ordinal: 380.
- Portuguese
- trezentos e oitenta· ordinal: 380º
Appears in sequences
- Number of necklaces with n beads of 2 colors, allowing turning over (these are also called bracelets).at n=13A000029
- a(n) = n^2*Product_{p|n} (1 + 1/p).at n=18A000082
- Number of bicentered hydrocarbons with n atoms.at n=13A000200
- Number of nondegenerate Boolean functions of n variables: For n > 0, a(n) = A000616(n) - A000616(n-1).at n=4A000618
- Expansion of Product (1 - x^k)^8 in powers of x.at n=42A000731
- No-3-in-line problem on n X n grid: total number of ways of placing 2n points on n X n grid so no 3 are in a line. No symmetries are taken into account.at n=7A000755
- Smallest k such that the product of q/(q-1) over the primes from prime(n) to prime(n+k-1) is greater than 2.at n=14A001276
- a(n) = (3*n+1)*(3*n+2).at n=6A001504
- Generalized sum of divisors function.at n=18A002132
- Numbers y such that p^2 = x^2 + y^2, 0 < x < y, p = A002144(n).at n=43A002365
- Let p = A007645(n) be the n-th generalized cuban prime and write p^2 = x^2 + 3*y^2 with y > 0; a(n) = y.at n=56A002368
- Oblong (or promic, pronic, or heteromecic) numbers: a(n) = n*(n+1).at n=19A002378
- Quarter-squares: a(n) = floor(n/2)*ceiling(n/2). Equivalently, a(n) = floor(n^2/4).at n=39A002620
- Number of integer points in a certain quadrilateral scaled by a factor of n.at n=28A002789
- a(n) = 2*n*(2*n-1).at n=10A002939
- Beginnings of periodic unitary aliquot sequences.at n=30A003062
- a(n) = floor(100*log_2(n)).at n=13A004262
- Number of symmetric irreducible diagrams with 2n nodes.at n=6A004300
- Triangle read by rows: the Bell transform of the triple factorial numbers A008544 without column 0.at n=18A004747
- a(n) = floor(n*phi^9), where phi is the golden ratio, A001622.at n=5A004924