16618
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 28512
- Proper Divisor Sum (Aliquot Sum)
- 11894
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7116
- Möbius Function
- -1
- Radical
- 16618
- Omega Function (Ω)
- 3
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 66
- 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
- From a nim-like game.at n=36A003413
- A simple grammar: partial sums of A008965.at n=18A052825
- Number of gap-free compositions of n.at n=15A107428
- Coefficients of the second order mock theta function B(q).at n=35A153140
- Number of partitions p of n such that 2(number of parts of p) - 2*min(p) is a part of p.at n=53A238588
- Poincaré series for hyperbolic reflection group with Coxeter diagram shown in Comments.at n=14A265051
- p-INVERT of the positive integers, where p(S) = 1 - 4*S + 2*S^2.at n=5A291183
- Number of integer partitions of n whose length times maximum is a multiple of n.at n=57A326849
- Number of partitions of n with rank 5 (the rank of a partition is the largest part minus the number of parts).at n=54A363214
- G.f. A(x) satisfies: A(x) = x + x^2 * exp( Sum_{k>=1} A(x^k)^2 / k ).at n=18A363385
- a(n) = (1/phi(n)) * Sum_{j=1..n} Sum_{k=1..n} phi(n*j*k).at n=18A372668
- G.f. A(x) satisfies A(x) = 1 + x*abs( 1/A(x) )^2.at n=16A380708