2828
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 5712
- Proper Divisor Sum (Aliquot Sum)
- 2884
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 1200
- Möbius Function
- 0
- Radical
- 1414
- 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
- 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
- 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
- Number of switching networks with S(n,2) acting on the domain and AG(3,2) acting on the range where S(n,k) is the symmetric group acting on k variables.at n=2A000887
- Numbers that are the sum of 7 positive 7th powers.at n=13A003374
- a(n) = floor(n*phi^10), where phi is the golden ratio, A001622.at n=23A004925
- Coordination sequence T1 for Zeolite Code AFO.at n=35A008015
- Coordination sequence T7 for Zeolite Code MEL.at n=34A008156
- Number of lines through exactly 3 points of an n X n grid of points.at n=18A018810
- Doublets: base-10 representation is the juxtaposition of two identical strings.at n=27A020338
- a(n) = T(2n-1,n), where T is the array in A026098.at n=25A026102
- a(n)/1000 gives sqrt(n) to 3 places after the decimal point.at n=7A027662
- Numbers k such that k*(k+8) is a palindrome.at n=15A028567
- 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 26.at n=31A031524
- Base 6 digits are, in order, the first n terms of the periodic sequence with initial period 2,1,0,3.at n=4A037732
- Numerators of continued fraction convergents to sqrt(816).at n=6A042574
- Numbers k such that the string 8,2 occurs in the base 9 representation of k but not of k-1.at n=37A044325
- Numbers n such that string 8,2 occurs in the base 9 representation of n but not of n+1.at n=37A044706
- Numbers whose base-4 representation contains exactly three 0's and two 3's.at n=21A045078
- Numbers whose consecutive digits differ by 6.at n=25A048408
- Numbers n such that 155*2^n-1 is prime.at n=12A050619
- Nonprime numbers k for which phi(k) + sigma(k) is an integer multiple of the cube of the number of divisors of k.at n=43A055467
- McKay-Thompson series of class 9c for the Monster group.at n=21A058095