4239
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 6320
- Proper Divisor Sum (Aliquot Sum)
- 2081
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2808
- Möbius Function
- 0
- Radical
- 471
- Omega Function (Ω)
- 4
- 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
- 82
- 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
- no
- Odd
- yes
Appears in sequences
- Number of ways writing 2^n as unordered sums of 2 primes.at n=20A006307
- Left diagonal of partition triangle A047812.at n=13A007044
- Number of partitions of n into parts of sizes {a( )} is a(n).at n=45A007209
- Coordination sequence T4 for Zeolite Code AET.at n=45A008010
- Number of SiC polytypes that repeat after 2n layers.at n=27A011959
- Pseudoprimes to base 82.at n=43A020210
- a(n) = 1*t(n) + 2*t(n-1) + ...+ k*t(n+1-k), where k=floor((n+1)/2) and t is A001950 (upper Wythoff sequence).at n=25A023867
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = A001950 (upper Wythoff sequence).at n=24A024864
- Expansion of g.f. (1+2*x+3*x^2)/(1-x-x^2-x^3-x^4).at n=12A028831
- a(n) = (2*n+1)*(12*n+1).at n=13A033576
- 14-gonal (or tetradecagonal) numbers: a(n) = n*(6*n-5).at n=27A051866
- Number of ways to cover (without overlapping) a ring lattice (necklace) of n sites with molecules that are 8 sites wide.at n=39A058365
- The array described in A059513 read by antidiagonals in the 'up' direction.at n=24A059574
- The array described in A059513 read by antidiagonals in the direction of construction.at n=24A059575
- Main diagonal of the array A059574.at n=3A059577
- Positive numbers whose product of digits is 12 times their sum.at n=36A062045
- Smallest multiple of n-th prime which is == 1 mod (n+1)-st prime.at n=36A073603
- Poincaré series [or Poincare series] (or Molien series) for a certain four-fold wreath product P_4.at n=38A091434
- a(n) = smallest k such that the base 4 Reverse and Add! trajectory of A075421(n) joins the trajectory of k.at n=40A091676
- Numbers n such that n^2+n+41 (Euler's "prime generating polynomial") is not squarefree.at n=24A097823