6448
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 13888
- Proper Divisor Sum (Aliquot Sum)
- 7440
- 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
- 2880
- Möbius Function
- 0
- Radical
- 806
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 23
- 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 series-reduced labeled trees with n nodes.at n=7A005512
- Number of Boolean functions realized by n-input cascades.at n=2A005619
- a(n) = n*(n+1)*(n+8)/6.at n=31A006503
- G:=1/product((1-x^(3k-2))*(1-x^(3k-1))^2*(1-x^(3k))^3,k=1..infinity).at n=19A029864
- Number of walks of length n between two vertices on an icosahedron at distance 2.at n=6A030518
- a(n) = T(7,n), array T given by A048505.at n=6A048512
- Number of isolated lucky numbers <= 10^n.at n=5A055725
- Expansion of ((1-x)/(1-2*x))^4.at n=8A062109
- Sum of terms in n-th row of A077164.at n=18A077167
- Number of positions that are exactly n moves from the starting position in the Rashkey Type 1 puzzle.at n=10A079844
- Another version of A005512, which is the main entry for this sequence.at n=6A096984
- Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having exactly k UDU's at low level.at n=57A098747
- Numbers n such that 9*10^n + 2*R_n - 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=13A103093
- Triangle read by rows: T(n,k) = number of Schroeder (or royal) n-paths (A006318) containing k returns to the diagonal y=x. (A northeast step lying on y=x contributes a return.)at n=31A108891
- Admirable numbers n such that the subtracted divisor is > sqrt(n).at n=24A109321
- 3*Volume of the root-n Waterman polyhedron of void-center type as defined in A119870.at n=35A119878
- 3*Volume of the root-n Waterman polyhedron of void-center type as defined in A119870.at n=34A119878
- Numbers k such that there is a bigger number m satisfying A000203(k) = A000203(m) = m + k - gcd(m,k).at n=22A124140
- Numbers n whose reverse binary representation has the following property: let a 0 mean "halving" and a 1 mean "k -> 3k+1". The number describes an operation k -> f_n(k). If the equation f_n(k) = k has a positive integer solution, n is a term in the sequence.at n=36A125756
- a(n) = (prime(n)^2 + prime(n+1))/2.at n=28A140511