13815
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
- 12
- Divisor Sum
- 24024
- Proper Divisor Sum (Aliquot Sum)
- 10209
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7344
- Möbius Function
- 0
- Radical
- 4605
- 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
- 120
- 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
- Numbers whose base-4 representation contains exactly three 1's and four 3's.at n=17A045128
- Partial sums of the central trinomial coefficients (A002426).at n=10A097893
- Odd integers that do not generate monotonically decreasing infinitary aliquot sequences.at n=30A127667
- Number of partitions of 9*n-8 into parts having in decimal representation digital root 1.at n=28A156145
- Sum of parts of the n-th subsection of the head of the last section of the set of partitions of any odd integer >= 2n+1.at n=14A182995
- Number of parts in all partitions of n in which no part occurs more than twice.at n=34A185350
- Number of nonempty subsets of {1, 2, ..., n} with <= 4 pairwise coprime elements.at n=38A187265
- Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w+x+y>=0.at n=15A211612
- Smallest k such that z = n in the minimal value of x + y*z, given x*y + z = k (for positive integers x, y, z).at n=8A228288
- Integers n of the form 8k+7 that are sum of distinct squares of the form m, m+1, m+2, m+4, where m == 1 (mod 4).at n=14A243578
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 449", based on the 5-celled von Neumann neighborhood.at n=28A272254
- Number of n element multisets of the 15th roots of unity with zero sum.at n=44A321418
- Numbers k such that 369*2^k+1 is prime.at n=16A323009