15872
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
- 20
- Divisor Sum
- 32736
- Proper Divisor Sum (Aliquot Sum)
- 16864
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7680
- Möbius Function
- 0
- Radical
- 62
- Omega Function (Ω)
- 10
- 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
- 115
- 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
- Generalized class numbers c_(n,2).at n=6A000362
- Number of alternating permutations of order n.at n=9A001250
- Number of points on surface of dodecahedron: a(n) = 30*n^2 + 2 for n > 0.at n=23A005903
- a(n) = n*(n+1)^2/2.at n=31A006002
- Triangle of Euler-Bernoulli or Entringer numbers read by rows: T(n,k) is the number of down-up permutations of n+1 starting with k+1.at n=46A008282
- Read across rows of Euler-Bernoulli or Entringer triangle.at n=29A008283
- Triangle read by rows: number of permutations of 1..n by length of longest run.at n=35A010026
- Triangle of Euler-Bernoulli or Entringer numbers.at n=53A010094
- E.g.f.: -log(cos(x)*cos(x)) (even powers only).at n=5A012509
- Expansion of sec(x)^2+sech(x)^2 in powers of x^4.at n=2A012853
- Number of partitions of n that do not contain 5 as a part.at n=38A027339
- Number of partitions satisfying (cn(2,5) = cn(3,5) and cn(2,5) <= cn(1,5) and cn(2,5) <= cn(4,5)).at n=50A036808
- Numbers that are divisible by exactly 10 primes with multiplicity.at n=35A046314
- Least k for which the integers Floor(k/(m*(m+1))) for m=1,2,...,n are distinct.at n=35A054061
- Triangle read by rows: T(n,k) is the number of permutations of [n] with k alternating runs (n>=2, k>=1).at n=35A059427
- Generalized Euler number c(7,n).at n=2A064068
- Triangle in which rows are permutations of the rows of A008282.at n=48A064192
- The sum of the non-divisors of n (less than n) is a multiple of the sum of the divisors of n.at n=16A066860
- Convolution of A075298 with A056594.at n=30A075495
- Numbers k such that sum of the divisors d of k divides 1 + 2 + ... + k = k(k+1)/2.at n=18A076617