2628
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 6734
- Proper Divisor Sum (Aliquot Sum)
- 4106
- 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
- 864
- Möbius Function
- 0
- Radical
- 438
- 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
- yes
- 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
- 53
- 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
- A Fielder sequence: a(n) = a(n-1) + a(n-2) + a(n-4).at n=13A001641
- a(n) = n^2 + prime(n).at n=48A004232
- Number of weighted voting procedures.at n=11A005256
- Coefficients of period polynomials.at n=19A006308
- Trails of length n on square lattice.at n=7A006817
- Coordination sequence T2 for Zeolite Code NAT.at n=34A008204
- a(n) = p*(p-1)/2 for p = prime(n).at n=20A008837
- Coordination sequence T2 for Zeolite Code DFO.at n=39A009876
- Coordination sequence T3 for Zeolite Code DFO.at n=39A009877
- High-temperature expansion for Ising model spin-spin correlation function on 4-d cubic lattice.at n=3A010563
- Second hexagonal numbers: a(n) = n*(2*n + 1).at n=36A014105
- Even triangular numbers.at n=36A014494
- Binomial coefficients C(n,71).at n=2A017735
- Binomial coefficients C(73,n).at n=2A017789
- Smallest triangular number that begins with n.at n=25A018855
- Convolution of the lower and upper Wythoff sequences (A000201 and A001950).at n=14A023664
- a(n) = Sum_{i=1..floor((n+1)/4)} a(2*i-1) * a(n-2*i+1), with a(1)=a(2)=1 and a(3)=4.at n=13A024727
- a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=a(2)=1 and a(3)=4.at n=12A024949
- a(n) = (prime(n)-3)*(prime(n)-5)/8.at n=33A030007
- Concatenation of n and n + 2 or {n,n+2}.at n=25A032607