1968
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 5208
- Proper Divisor Sum (Aliquot Sum)
- 3240
- 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
- 640
- Möbius Function
- 0
- Radical
- 246
- Omega Function (Ω)
- 6
- 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
- 50
- 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 n-step polygons on hexagonal lattice.at n=8A001335
- Numbers k such that (k^2 + k + 1)/19 is prime.at n=44A002643
- Ferromagnetic susceptibility series for f.c.c. lattice.at n=20A002924
- a(n) = round(n*phi^10), where phi is the golden ratio, A001622.at n=16A004945
- a(n) = ceiling(n*phi^10), where phi is the golden ratio, A001622.at n=16A004965
- Coordination sequence T1 for Zeolite Code CHA.at n=34A008066
- Coordination sequence T6 for Zeolite Code DDR.at n=28A008076
- Coordination sequence T9 for Zeolite Code MFI.at n=28A008172
- E.g.f. log(1 + sin(x)*exp(x)).at n=8A009340
- Coordination sequence T1 for Zeolite Code -WEN.at n=32A009862
- Coordination sequence T2 for Zeolite Code RSN.at n=29A009886
- Super-3 Numbers (3n^3 contains substring '333' in its decimal expansion).at n=14A014569
- Numbers k such that phi(k) + 11 | sigma(k).at n=7A015804
- Squares on infinite chessboard at n moves from center using a {2,3} fairy knight.at n=30A018839
- Numbers whose base-9 representation is the juxtaposition of two identical strings.at n=23A020337
- Index of 5^n within sequence of numbers of form 3^i*5^j.at n=51A022338
- n-th 8k+1 prime plus n-th 8k+7 prime.at n=39A022761
- Discriminants of quartic fields with 2 complex conjugates (negated).at n=46A023681
- Number of 2's in all partitions of n.at n=22A024786
- a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 4. Also a(n) = T(n,n-4), where T is the array defined in A025177.at n=6A025182