11556
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 30240
- Proper Divisor Sum (Aliquot Sum)
- 18684
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3816
- Möbius Function
- 0
- Radical
- 642
- 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
- yes
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 143
- 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(n) = round(n*phi^18), where phi is the golden ratio, A001622.at n=2A004953
- a(n) = ceiling(n*phi^18), where phi is the golden ratio, A001622.at n=2A004973
- Coordination sequence for MgZn2, Position Zn2.at n=27A009938
- Fibonacci sequence beginning 2, 6.at n=17A022112
- a(n) = least m such that if r and s in {|F(h+1)-tau*F(h)|: h = 1,2,...,n} satisfy r < s, then r < k/m < s for some integer k, where F = A000045 (Fibonacci numbers) and tau = (1+sqrt(5))/2 (golden ratio).at n=18A024849
- Product of a prime and the following number.at n=27A036690
- a(n) = prime(n)*prime(n+1) - prime(n).at n=27A037166
- Numbers k such that sigma(k) = 2*usigma(k).at n=33A063880
- Numbers k such that the period of the continued fraction for sqrt(5)*k is 2.at n=32A065030
- a(n) = (sum of first n primes)^2 + sum of (squares of first n primes).at n=8A065762
- Numbers k such that sigma(k) divides sigma(sigma(k)).at n=29A066961
- Numbers n such that sigma(n) = phi(prime(n)+1).at n=22A067625
- Triangle of numbers {a(n,k), n >= 0, 0<=k<=n} defined by a(0,0)=1, a(n+1,0)=A006319(n)=a(n,0) + Sum a(k,k), k=0..n-1. a(n,m+1)= a(n,0) + Sum A006319(k)*a(n-k-1,0), k=0..m-1.at n=32A073151
- Sum of Lucas numbers and reflected Lucas numbers (comment to A061084).at n=18A075091
- Non-balanced numbers in A015771.at n=20A078549
- Numbers k such that the largest prime power factor of k equals floor(sqrt(k)).at n=44A081807
- Number of partitions of 2*n with no part divisible by 3 and all odd parts occurring with even multiplicities.at n=28A098151
- Second row of array in A101385.at n=17A101644
- a(n) = 4*n*(4*n - 1).at n=27A104188
- a(n) = number of conjugacy classes in PSL_3(prime(n)).at n=27A124679