15890
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
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 32832
- Proper Divisor Sum (Aliquot Sum)
- 16942
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- yes
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5424
- Möbius Function
- 1
- Radical
- 15890
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 128
- 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
- yes
- Odd
- no
Appears in sequences
- Weird numbers: abundant (A005101) but not pseudoperfect (A005835).at n=22A006037
- a(n) = [ a(n-1)/a(1) ] + [ a(n-3)/a(3) ] + [ a(n-5)/a(5) ] + ..., for n >= 3.at n=36A022878
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 18.at n=13A031696
- Unitary weird numbers: unitary abundant (A034683) but not unitary pseudoperfect (A293188).at n=19A064114
- Numbers n such that 4*10^n + 3*R_n + 6 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=17A102990
- Moebius transform of binomial(n+3, 4).at n=23A117109
- 324n^2 + 2n.at n=6A158271
- a(n) = 196*n^2 + 14.at n=9A158555
- Expansion of x*(1+2*x+8*x^2+4*x^3+3*x^4) / ( (1+x)^2*(x-1)^4 ).at n=27A178947
- Number of non-monotonic functions from [k] to [n-k].at n=30A189711
- Number of non-equivalent ways to choose two points in an equilateral triangle grid of side n.at n=28A227327
- Bi-unitary weird numbers: bi-unitary abundant numbers (A292982) that are not bi-unitary pseudoperfect (A292985).at n=24A292986
- Numbers k such that Bernoulli number B_{k} has denominator 4686.at n=10A295770
- Infinitary weird numbers: infinitary abundant numbers (A129656) that are not infinitary pseudoperfect numbers (A306983).at n=24A306984
- The number of edges formed on an isosceles triangle by straight line segments mutually connecting all vertices and all points that divide the two equal length sides into n equal parts; the base of the triangle contains no points other than its vertices.at n=13A333027
- Nonexponential weird numbers: nonexponential abundant numbers (A348604) that are not equal to the sum of any subset of their nonexponential divisors.at n=17A348631
- (1+e)-weird numbers: (1+e)-abundant numbers k such that no subset of the aliquot (1+e)-divisors of k sums to k.at n=18A349285
- Partial sums of A071619.at n=41A358042
- S-weird numbers: S-abundant numbers (A181487) k such that no subset of the aliquot divisors of k that are in the set S sums to k, where S is the set defined in A118372.at n=37A364862
- a(n) = index of 2*prime(n) in A381019.at n=30A379811