16642
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 25596
- Proper Divisor Sum (Aliquot Sum)
- 8954
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8112
- Möbius Function
- -1
- Radical
- 16642
- 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
- 53
- 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
- Numbers that are the sum of 5 positive 7th powers.at n=23A003372
- Numbers n such that n is a substring of its square in base 8 (written in base 10).at n=16A018832
- Ooguri-Vafa invariants of disk domain wall degeneracies for brane I in the O(K) -> P^1 X P^1 geometry.at n=1A061623
- When expressed in base 3 and then interpreted in base 5, is a multiple of the original number.at n=17A062864
- Numbers n with property that for each single digit d of n, we can also see the decimal expansion of 2^d as a substring of n. Also n may not contain any zero digits.at n=12A135016
- Numbers which converge to 2592 under repeated application of the powertrain map of A133500.at n=13A135384
- Triangular array: the fission of (p(n,x)) by (q(n,x)), where p(n,x)=sum{F(k+1)*x^(n-k) : 0<=k<=n}, where F=A000045 (Fibonacci numbers) and q(n,x)=(x+1)^n.at n=50A193997
- Mirror of the triangle A193997.at n=49A193998
- Number of (w,x,y,z) with all terms in {1,...,n} and w < (geometric mean of x,y,z).at n=14A212141
- a(n) = 9*n^2 + 1.at n=43A247792
- a(n) = Sum_{k=0..floor(n/3)} 2^k * Stirling2(n,3*k).at n=9A357782
- a(n) = floor( ((a(n-1) + 1) / 2)^2 ) + 1 for n >= 1, with a(0) = 0.at n=8A363257