6843
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9128
- Proper Divisor Sum (Aliquot Sum)
- 2285
- 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
- 4560
- Möbius Function
- 1
- Radical
- 6843
- 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
- 137
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = floor( n*(n-1)*(n-2)/23 ).at n=55A011905
- Number of partitions of n into parts having a common factor.at n=62A018783
- a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026758.at n=6A027232
- Numbers having period-2 6-digitized sequences.at n=23A031357
- 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 27.at n=33A031525
- Numbers whose base-4 representation contains exactly four 2's and two 3's.at n=16A045155
- Becomes prime after exactly 7 iterations of f(x) = sum of prime factors of x.at n=6A047826
- a(n) = Sum_{d|n} p(d), where p(d) = A000041 = number of partitions of d.at n=30A047968
- a(n) = 1 + (number of partitions of n, n>0).at n=31A052810
- Expansion of 1/(1+x^2-2*x^3).at n=30A077912
- Expansion of 1/(1+x^2+2*x^3).at n=30A077963
- Semiprimes (A001358) whose digit reversal is a triangular number.at n=31A115741
- a(n) = least k such that the remainder when 19^k is divided by k is n.at n=15A128159
- Integer quartets a(4k)= 2, a(4k+1) = 32*k^2-24*k+3, a(4k+2) = 32*k^2-24*k+2, a(4k+3) = 8*k-3, k>=1.at n=57A162155
- Antidiagonally reading the array, formed via: first, writing the primes in the first row (row_1), and forming all successive rows' elements using the previous rows' elements as: row_2(j) = row_1(j)*row_1(j+1) - row_1(j) - row_1(j+1), and so on. The first 'column' of the array, 2 1 -1 -1 -1 -1 -1 -1 ... is converted to its absolute value.at n=18A165401
- Positive integers of the form (2*m^2+1)/11.at n=35A179088
- Parameters n for which the elliptic curve y^2=x^3-n has rank 4.at n=7A179137
- Largest term in wrecker ball sequence starting with n.at n=7A248953
- Numbers m, such that the smallest prime factor of 1+78557*2^m doesn't belong to the covering set {3, 5, 7, 13, 19, 37, 73}.at n=20A258095
- A specially constructed B_2 sequence with sum of reciprocals greater than that of the Mian-Chowla sequence A005282.at n=57A259964