11865
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 21888
- Proper Divisor Sum (Aliquot Sum)
- 10023
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5376
- Möbius Function
- 1
- Radical
- 11865
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 73
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- yes
- 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
- a(n) = dot_product(1,2,...,n)*(7,8,...,n,1,2,3,4,5,6).at n=28A026049
- Numbers n such that phi(n) + phi(n+1) = sigma(n)/2.at n=13A076647
- Expansion of (1 + x)/(1 + x + 3*x^2).at n=17A110523
- Odd terms of A059756.at n=10A111042
- A(n,k,m) is the number of permutations of an n-set with k disjoint cycles of length less than or equal to m, called the (n,k)-th m-restrained Stirling numbers of the first kind, and denoted by mS_1(n,k). The sequence shows the case of m=3.at n=40A171996
- a(1)=4. a(n) = a(n-1) + n, if a(n-1)+n is composite. Otherwise a(n) = a(n-1)*n.at n=14A175459
- Numbers k such that 27*k+1 is a square.at n=41A219258
- Number of partitions p of n such that (maximal multiplicity of the parts of p) > (number of distinct parts of p).at n=38A240309
- Record values in A243145.at n=48A299112
- Number of binary strings of length n whose only palindromic prefixes are "1" and "11".at n=16A307909
- Triangle read by rows: T(n,k) is the number of labeled forests with n trees and 2n nodes and with the largest tree having at most k nodes, (n>=1, 2<=k<=n+1).at n=8A332961
- Odd composite integers m such that A086902(2*m-J(m,53)) == 7*J(m,53) (mod m), where J(m,53) is the Jacobi symbol.at n=45A339520
- Squarefree numbers k for which Q(k) - 6*k/Pi^2 sets a new record minimum, where Q(x) is the number of squarefree numbers up to x.at n=17A339865
- Number of integer partitions of n with parts colored by {0, 1, 2} such that the sum of colors is congruent to 0 (mod 3).at n=15A389343