4006
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 6012
- Proper Divisor Sum (Aliquot Sum)
- 2006
- 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
- 2002
- Möbius Function
- 1
- Radical
- 4006
- 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
- 144
- 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 odd integers <= 2^n of form x^2 + y^2.at n=14A000074
- 'Eban' numbers (the letter 'e' is banned!).at n=42A006933
- Coordination sequence T1 for Zeolite Code BOG.at n=45A008049
- Coordination sequence for FeS2-Marcasite, Fe position.at n=31A009955
- n written in fractional base 8/4.at n=38A024646
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n+1-k), where k = [ (n+1)/2 ], s = A000201 (lower Wythoff sequence).at n=25A024685
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5,..., 1/(2n-1)} satisfy r < s, then r < k/m < s for some integer k.at n=50A024819
- a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence).at n=24A025118
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 62.at n=11A031560
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 46 ones.at n=5A031814
- a(n) = Sum_{i=0..2} binomial(Fibonacci(n),i).at n=11A032441
- Becomes prime after exactly 6 iterations of f(x) = sum of prime factors of x.at n=39A047825
- Number of colors that can be mixed with up to n units of yellow, blue, red.at n=29A048134
- Smallest palindrome greater than n in bases n and n+1.at n=42A048268
- Numbers k for which there exists some m such that k = Sum_{i=1..1+floor(log_10(k))} binomial(m, d_i), where d_i is the i-th digit of k.at n=19A055481
- a(0)=1; a(n) = Sum_{j<n, gcd(n,a(j)) = 1} a(j).at n=25A055935
- Nearest integer to (Product(n^((1 + log(1 + i))/(1 + i^2)), {i, 1, n})).at n=37A062493
- Numbers with no zeros in their cubes such that the products of the digits of their cubes are also cubes.at n=25A067071
- Numbers k such that k+1, k^2+1 and k^4+1 are primes.at n=22A070325
- Smallest n-digit number beginning with n and having n divisors, or 0 if no such number exists.at n=3A077515