2728
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- yes
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 5760
- Proper Divisor Sum (Aliquot Sum)
- 3032
- 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
- 1200
- Möbius Function
- 0
- Radical
- 682
- Omega Function (Ω)
- 5
- 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
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 14
- Smith Number
- no
- Vampire 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
Appears in sequences
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^5)*(1-x^10)*(1-x^20)).at n=40A001305
- a(n) = n concatenated with n + 1.at n=26A001704
- a(n) = floor(n*phi^15), where phi is the golden ratio, A001622.at n=2A004930
- a(n) = round(n*phi^15), where phi is the golden ratio, A001622.at n=2A004950
- Kaprekar numbers: positive numbers n such that n = q+r and n^2 = q*10^m+r, for some m >= 1, q >= 0 and 0 <= r < 10^m, with n != 10^a, a >= 1.at n=9A006886
- Kaprekar triples: q such that q = x + y + z and q^3 = x*10^2n + y*10^n + z, where z < 10^n and n is the number of digits in q. q is not a power of 10 (except q=1).at n=5A006887
- Coordination sequence T2 for Zeolite Code AFY.at n=43A008030
- Coordination sequence T1 for Zeolite Code EAB.at n=38A008082
- Coordination sequence T1 for Zeolite Code ERI and OFF.at n=38A008093
- a(n) = floor(n*(n-1)*(n-2)/12).at n=33A011894
- Barlow packings with group R3(bar)m(SO) that repeat after 6n+3 layers.at n=12A011954
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly three 1's.at n=37A013650
- Pisot sequence T(6,10), a(n) = floor(a(n-1)^2/a(n-2)).at n=14A020741
- Fibonacci sequence beginning 2, 6.at n=14A022112
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A023531, t = (Lucas numbers).at n=15A024882
- Number of partitions of n with distinct parts p(i) such that if i != j, then |p(i) - p(j)| >= 3.at n=70A025157
- a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026747.at n=5A027224
- Pair up the numbers.at n=13A030655
- Numbers with the property that all pairs of consecutive base-5 digits differ by more than 2.at n=41A032982
- Concatenation of two or more consecutive positive integers.at n=35A035333