6897
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 30
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 10640
- Proper Divisor Sum (Aliquot Sum)
- 3743
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3960
- Möbius Function
- 0
- Radical
- 627
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 106
- 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
- no
- Odd
- yes
Appears in sequences
- Number of ordered trees with n edges and having no branches of length 1.at n=16A026418
- Number of partitions satisfying cn(0,5) + cn(1,5) <= cn(2,5) and cn(0,5) + cn(1,5) <= cn(3,5) and cn(0,5) + cn(4,5) <= cn(2,5) and cn(0,5) + cn(4,5) <= cn(3,5).at n=43A039882
- Denominators of continued fraction convergents to sqrt(365).at n=5A041691
- If m = p_i^e_i, n=Product p_j^f_j, set G_m(n) = Product p_{j+i}^{f_j*e_i}; extend G_m to all m by multiplicativity; sequence gives a(n)=G_n(n).at n=13A045974
- 15-gonal (or pentadecagonal) numbers: n*(13n-11)/2.at n=33A051867
- a(n) = Sum_{d|3} phi(d)*n^(3/d).at n=19A054602
- Numbers primitive with respect to having more than one factorization into S-primes. See related sequences for definition.at n=36A057950
- Numbers k such that sopf(k) = sopf(k+3), where sopf(k) = A008472(k).at n=13A063969
- Numbers that are sums of divisors of the odd squares; Intersection of A065764 and A065766, written in ascending order and duplicates removed.at n=36A065768
- Triangle read by rows of numbers of paths in a lattice satisfying certain conditions.at n=46A071950
- Numbers k such that sigma(sigma(k)-k) = phi(k).at n=8A074875
- Number of + signs needed to write the partitions of n (A000041) as sums.at n=22A076276
- Numbers k such that 10^k + 5*R_k + 4 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=16A102938
- Triangle T(n, k, m) = t(n,m)/( t(k,m) * t(n-k,m) ) with T(n, 0, m) = T(n, n, m) = 1, where t(n, m) = Product_{j=1..n} Product_{i=1..j-1} ( 1 - (m+1)*(2*i-1) ) and m = 3, read by rows.at n=12A156698
- Numbers k such that phi(phi(k)) = sigma(rad(k)).at n=16A173748
- Riordan matrix (g(x),x*g(x)), where g(x) = (1-x-sqrt(1-2*x-3*x^2-4*x^3))/(2*x^2*(1+x)).at n=57A190252
- Numbers k such that 19*k+1 is a square.at n=38A219396
- Number of tilings of an n X 1 rectangle (using tiles of dimension 1 X 1 and 2 X 1) that are not the concatenation of smaller equally-sized tilings.at n=21A224918
- a(0) = 1, a(1) = 19; for n > 1, a(n) = 19*a(n-1) + a(n-2).at n=3A243399
- Numbers m such that (4^m + 23) / 3 is prime.at n=17A261579