6827
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6828
- 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
- 6826
- Möbius Function
- -1
- Radical
- 6827
- 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
- 181
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 878
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Sum of 12 nonzero 8th powers.at n=14A003390
- Primes that are palindromic in base 2 (but written here in base 10).at n=25A016041
- Expansion of 1/(1-x^5-x^6-x^7-x^8-x^9).at n=45A017840
- 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 81.at n=21A031579
- Numbers with exactly five distinct base-9 digits.at n=31A031986
- Trajectory of 1 under map n->9n+1 if n odd, n->n/2 if n even.at n=25A033962
- Trajectory of 3 under map n->9n+1 if n odd, n->n/2 if n even.at n=35A037102
- Bends in loxodromic sequence of spheres in which each 5 consecutive spheres are in mutual contact.at n=15A045626
- Discriminants of imaginary quadratic fields with class number 17 (negated).at n=17A046014
- a(1) = 7; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=45A046257
- Integers n such that A047988(n)=3.at n=30A047986
- a(n) = a(n-1) + 2*a(n-2), a(0)=2, a(1)=3.at n=12A048573
- Family 1 "Rule 90 x Rule 150 Array" read by antidiagonals.at n=26A048710
- 2nd column of Family 1 "90 X 150 array": generations 0 .. n of Rule 150 starting from seed pattern 5.at n=5A048712
- First term of weak prime quintets: p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2) < p(m+4)-p(m+3).at n=18A054823
- McKay-Thompson series of class 52A for Monster.at n=58A058705
- Number of partitions of n in which number of parts is not 2.at n=31A058984
- phi(s(n^3)) is a square, where s(n) is sigma(n)-n (A001065).at n=17A063798
- Primes which, although they have correct parity, are not in the prime number maze.at n=4A065123
- a(n+3) = floor( ( a(n) + 2*a(n+1) + 3*a(n+2) )/4 ), with a(0), a(1), a(2) equal to 0, 1, 2.at n=37A074732