15986
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 23982
- Proper Divisor Sum (Aliquot Sum)
- 7996
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7992
- Möbius Function
- 1
- Radical
- 15986
- 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
- 84
- 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
- yes
- Odd
- no
Appears in sequences
- Number of partitions with no even part repeated; partitions of n in which no parts are multiples of 4.at n=42A001935
- Number of partitions of 2n in which no parts are multiples of 4.at n=21A081055
- Expansion of psi(x) / phi(x) in powers of x where phi(), psi() are Ramanujan theta functions.at n=42A083365
- Expansion of x*(1-6*x+7*x^2)/((1-x)*(1+x)*(1-5*x+x^2)).at n=9A107389
- Greatest number m such that the fractional part of (1024/1000)^A153680(n) >= 1-(1/m).at n=10A153684
- Number of nondecreasing integer sequences of length 8 with sum zero and sum of absolute values 2n.at n=18A158142
- Number of admissible sequences of order j; related to 7x+1 problem.at n=7A174796
- Expansion of phi(-x^6)^2 / (chi(x) * phi(-x)^2) in powers of x where phi(), chi() are Ramanujan theta functions.at n=14A260545
- Expansion of f(-x^3) * f(-x^6) / (f(x) * f(-x^4)) in powers of x where f() is a Ramanujan theta function.at n=32A261252
- Twice-partitioned numbers where the first partition is strict and the latter partitions are constant.at n=29A279786
- Number of nX4 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=7A300772
- T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=58A300776
- T(n,k)=Number of nXk 0..1 arrays with every element equal to 2, 3, 4 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=62A300776
- Triangle read by rows: T(n, k) = n! * 2^k * hypergeom([-k], [-n], 1/2).at n=25A374428
- a(n) is the number of complement pairs of primitive 2n-bead balanced binary necklaces.at n=11A383904
- a(n) is the number of complement pairs of 2n-bead balanced bicolor necklaces.at n=11A386388
- a(n) is the number of complement pairs of imprimitive (periodic) 2n-bead balanced binary necklaces.at n=22A387130