2838
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 6336
- Proper Divisor Sum (Aliquot Sum)
- 3498
- 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
- 840
- Möbius Function
- 1
- Radical
- 2838
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 128
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
Appears in sequences
- a(n) is the smallest positive integer a for which there is an identity of the form a*n*x = Sum_{i=1..m} ai*gi(x)^n where a1, ..., am are in Z and g1(x), ..., gm(x) are in Z[x].at n=43A005729
- a(n) = floor(n*(n+2)*(2*n-1)/8).at n=21A007518
- Coordination sequence T5 for Zeolite Code EUO.at n=33A008100
- Coordination sequence T5 for Zeolite Code GOO.at n=36A008115
- Coordination sequence T2 for Zeolite Code -ROG.at n=40A009860
- Coordination sequence T3 for Zeolite Code -ROG.at n=40A009861
- a(n) = floor( n*(n-1)*(n-2)/28 ).at n=44A011910
- a(n) = floor(n*(n-1)*(n-2)/30).at n=45A011912
- Numbers n such that phi(n) * sigma(n) + 9 is a perfect square.at n=34A015728
- a(n) = [ a(n-1)/a(1) ] + [ a(n-3)/a(3) ] + [ a(n-5)/a(5) ] + ..., for n >= 3.at n=21A022860
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = (odd natural numbers).at n=16A024592
- s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = (composite numbers).at n=19A025102
- Number of partitions of n into an even number of parts, the least being 6; also, a(n+6) = number of partitions of n into an odd number of parts, each >=6.at n=73A027198
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 52.at n=8A031550
- "AGK" (ordered, elements, unlabeled) transform of 2,2,2,2...at n=10A032023
- Coordination sequence T2 for Zeolite Code SBS.at n=42A033609
- Number of different sets ("cut sets") of triangles a regular (n+2)-gon can be dissected into; two triangulations of an (n+2)-gon are equal if all numbers of congruent triangles coincide.at n=15A033961
- First differences give (essentially) A028242.at n=28A035107
- G.f.: 1/((1-x)*(1-x^2))^3.at n=15A038163
- Growth function (or coordination sequence) of the infinite cubic graph corresponding to the srs net (a(n) = number of nodes at distance n from a fixed node).at n=46A038620