2028
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 5124
- Proper Divisor Sum (Aliquot Sum)
- 3096
- 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
- 624
- Möbius Function
- 0
- Radical
- 78
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 37
- 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
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); A000092 gives values of n where |P(n)| sets a new record; sequence gives (nearest integer to, I believe) P(A000092(n)).at n=42A000223
- Number of tournaments on n nodes determined by their score vectors.at n=15A000570
- a(n) = number of special odd permutations of 2*n+1.at n=4A003110
- Numbers that are the sum of 6 positive 5th powers.at n=47A003351
- Expansion of (1+x^2) / ( (1-x)^2 * (1-x^3)^2 ).at n=35A006501
- Sum of spans of 2n-step polygons on square lattice.at n=6A006772
- a(n) = floor(n/4)*floor((n+1)/4)*floor((n+2)/4).at n=51A008218
- Coordination sequence for FeS2-Marcasite, S position.at n=22A009954
- Expansion of (1+2*x+3*x^2)/((1-x)*(1-x^2)^2).at n=51A014255
- Powers of fourth root of 6 rounded down.at n=17A018060
- Powers of fourth root of 6 rounded to nearest integer.at n=17A018061
- a(n) = n*(7*n + 1)/2.at n=24A022265
- Number of partitions of n into 7 unordered relatively prime parts.at n=31A023027
- A B_2 sequence: a(n) is the least value such that sequence increases and pairwise sums of elements are all distinct.at n=35A025582
- Numbers with 18 divisors.at n=33A030636
- 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 30.at n=12A031528
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 30.at n=2A031708
- Concatenation of n and n + 8 or {n,n+8}.at n=19A032613
- a(n) = 3*n^2.at n=26A033428
- Numbers that can be expressed as the product of three 2-digit numbers.at n=41A033830