6812
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 12936
- Proper Divisor Sum (Aliquot Sum)
- 6124
- 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
- 3120
- Möbius Function
- 0
- Radical
- 3406
- Omega Function (Ω)
- 4
- 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
- 62
- 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
- yes
- Odd
- no
Appears in sequences
- Fibonacci sequence beginning 2, 28.at n=13A022376
- Number of partitions of n into parts not of the form 11k, 11k+5 or 11k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 4 are greater than 1.at n=37A035948
- Starting from generation 7 add previous and next term yielding generation 8.at n=15A048454
- Difference between length (A005341) and sum of digits (A004977) of n-th term in Look and Say Sequence (A005150).at n=32A056635
- Numbers k for which the sums of prime factors (ignoring multiplicity) of sigma(k) and phi(k) are equal but the sets of prime factors of sigma and phi are different.at n=25A081378
- A000041(n)-A000010(n).at n=30A086739
- a(n) = (Sum_{k=1..n} A073698(k))^(1/n).at n=46A093928
- Numbers n such that 5*10^n + 6*R_n + 3 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=20A103018
- n times n+9 gives the concatenation of two numbers m and m+6.at n=5A116334
- Numbers k for which 8*k+1, 8*k+3 and 8*k+7 are primes.at n=36A123978
- Shifts 3 places left under Dirichlet convolution.at n=37A144367
- Partial sums of A027444.at n=12A152457
- Coefficients of the second order mock theta function B(q).at n=30A153140
- Greatest number m such that the fractional part of (101/100)^A153671(m) >= 1-(1/m).at n=74A153675
- Number of distinct solutions of sum{i=1..2}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.at n=33A180794
- Numbers n such that d(n-1) = d(n+1) = 6, where d(k) is the number of divisors of k (A000005).at n=26A190267
- G.f.: A(x) = x/(1-x) o x/(1-x^3) o x/(1-x^5) o x/(1-x^7) o..., a composition of functions x/(1-x^(2*n-1)) for n=1,2,3,...at n=19A206720
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having two or three distinct values for every i<=n and j<=n.at n=8A211461
- Numbers k such that 3^k - 8 is prime.at n=17A217135
- a(n) is the least k such that f(a(n-1)+1) + ... + f(k) > f(a(n-2)+1) + ... + f(a(n-1)) for n > 1, where f(n) = 1/(n+3) and a(1) = 1.at n=7A225918