11885
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14268
- Proper Divisor Sum (Aliquot Sum)
- 2383
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9504
- Möbius Function
- 1
- Radical
- 11885
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 50
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Numbers n such that 1n1, 3n3, 7n7 and 9n9 are all primes.at n=27A059677
- a(n) is the difference between A084321(n) and the (n-1)th power of 2.at n=27A085355
- Row sums of inverse of sequence array for Euler phi function.at n=40A106480
- First differences of values of n for Cullen primes in A005849.at n=4A128193
- Number of line graphs on n labeled nodes.at n=5A132219
- Indices of record high-points in the sequence of Sprague-Grundy values for Grundy's game.at n=40A180120
- Number of (w,x,y,z) with all terms in {0,...,n} and 2w-x=max{w,x,y,z}-min{w,x,y,z}.at n=28A212756
- Numbers n where tau(n) and n-tau(n) are perfect squares, with tau(n) the number of divisors of n (A000005).at n=28A245197
- Number of length n arrays of permutations of 0..n-1 with each element moved by -2 to 2 places and with no two consecutive increases.at n=20A263637
- a(n) = prime(1)^2 + prime(n)^2.at n=28A287922
- Expansion of Product_{k>=1} 1/(1 - x^k)^(3*k*(k-1)/2+1).at n=10A295179
- Number of integer partitions of n whose omega-sequence has repeated parts.at n=34A325285
- Numbers k such that lcm(1,2,3,...,k)/23 equals the denominator of the k-th harmonic number H(k).at n=4A342351
- Semiprimes of the form k^2 + 4.at n=23A360741
- a(n) is the difference between the sum of the squares and the sum of the cubes for the n first terms of A002760.at n=42A374754
- a(n) is the smallest possible side x in a family of triangles with integer sides x, y < x, x-y < z < x+y, such that exactly n pairs of triangles with equal area exist in this family.at n=43A375748