6841
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6842
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 6840
- Möbius Function
- -1
- Radical
- 6841
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 57
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 881
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- -1 + number of partitions of n.at n=31A000065
- Number of partitions of n into relatively prime parts. Also aperiodic partitions.at n=31A000837
- Primes p such that the multiplicative order of 2 modulo p is (p-1)/4.at n=42A001134
- Artiads: the primes p == 1 (mod 5) for which Fibonacci((p-1)/5) is divisible by p.at n=42A001583
- From a Goldbach conjecture: records in A185091.at n=41A002092
- Quintan primes: p = (x^5 - y^5)/(x - y).at n=7A002649
- Number of partitions of {1..2n} that are invariant under a permutation consisting of n 2-cycles.at n=6A002872
- Primes p == 1 (mod 8), p = a^2 +64*b^2 such that y^2 = x^3 + p*x has rank 0.at n=32A007765
- Expansion of g.f. 1/((1-5*x)*(1-7*x)).at n=4A016161
- Largest integer in which every prefix is prime in base n (written in base 10).at n=4A023107
- Primes that remain prime through 3 iterations of function f(x) = 3x + 10.at n=38A023280
- Numbers n such that n divides the (right) concatenation of all numbers <= n written in base 7 (most significant digit on right).at n=12A029500
- Smallest prime containing n-th square as substring.at n=29A029948
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 7.at n=16A031420
- Lower prime of a pair of consecutive primes having a difference of 16.at n=22A031934
- Incrementally largest terms in the continued fraction for zeta(3).at n=14A033166
- Primes of the form p^k - p + 1 for prime p.at n=14A034915
- Number of partitions of n with equal number of parts congruent to each of 1, 3 and 4 (mod 5).at n=55A035580
- Denominators of continued fraction convergents to sqrt(559).at n=10A042071
- Smallest number which can be written as the sum of distinct Fibonacci numbers in n ways and such that the Zeckendorf representation of the number uses only even-subscripted Fibonacci numbers.at n=37A046815