4075
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 5084
- Proper Divisor Sum (Aliquot Sum)
- 1009
- 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
- 3240
- Möbius Function
- 0
- Radical
- 815
- Omega Function (Ω)
- 3
- 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
- 157
- 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
- Coordination sequence T1 for Zeolite Code AFO.at n=42A008015
- Poincaré series [or Poincare series] (or Molien series) for mod 2 cohomology of universal W-group W(5).at n=5A014700
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly five 1's.at n=35A020441
- a(n) = n*(13*n + 1)/2.at n=25A022271
- Number of partitions of n that do not contain 10 as a part.at n=29A027344
- Ranks of certain relations among Euler sums of weight n.at n=11A038360
- Numbers whose base-4 representation contains exactly two 2's and four 3's.at n=12A045147
- Numbers k such that k and k+1 both have 6 divisors.at n=41A049103
- Sum of the first n Sophie Germain primes.at n=23A066819
- Largest eigenvalue, rounded to the nearest integer, of a rank n matrix of 1..n^2 filled successively along rows.at n=19A072333
- Smaller of two consecutive numbers of the form p^2*q where p and q are distinct primes.at n=39A074172
- Partial sums of A084263.at n=28A084570
- Triangle of coefficients, read by row polynomials P_n(y), that satisfy the g.f.: A096651(x,y) = Product_{n>=1} 1/(1-x^n)^[P_n(y)/n], with P_n(0)=0 for n>=1.at n=48A096800
- The partition function G(n,5).at n=8A110038
- 3-almost primes that are the sum of 2 positive cubes. Sums of 2 positive cubes, with the sums having exactly 3 prime divisors counted with multiplicity.at n=15A122732
- Let f(k) = exp(Pi*sqrt(k)); sequence gives numbers k such that ceiling(f(k)) - f(k) < 1/10^3.at n=17A127022
- Let f(n) = exp(Pi*sqrt(n)); sequence gives numbers n such that ceiling(f(n)) - f(n) < 1/10^4.at n=8A127023
- Let f(n) = exp(Pi*sqrt(n)); sequence gives numbers n such that ceiling(f(n)) - f(n) < 1/10^5.at n=5A127024
- a(n) = Sum_{k=1 to d(n)} C(d(n)-1, k-1) d_k, where d(n) is the number of divisors of n and d_k is the k-th divisor of n.at n=47A132065
- a(1)=1, a(n)=a(n-1)+n^0 if n odd, a(n)=a(n-1)+ n^2 if n is even.at n=28A135301