6819
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9096
- Proper Divisor Sum (Aliquot Sum)
- 2277
- 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
- 4544
- Möbius Function
- 1
- Radical
- 6819
- 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
- Numbers that are the sum of 7 positive 7th powers.at n=23A003374
- Numbers that are the sum of 4 nonzero 8th powers.at n=6A003382
- Numbers that are the sum of at most 4 nonzero 8th powers.at n=21A004877
- Numbers that are the sum of at most 5 nonzero 8th powers.at n=28A004878
- Numbers that are the sum of at most 6 nonzero 8th powers.at n=36A004879
- Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12).at n=34A017834
- Cycle class sequence c(2n) (the number of true cycles of length 2n in which a certain node is included) for zeolite LTN = Linde Type N Na384[Al384Si384O1536].518H2O starting with a T3 atom.at n=5A019038
- 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=19A031579
- Number of partitions satisfying 0 < cn(0,5) + cn(1,5) + cn(2,5) + cn(3,5) and 0 < cn(0,5) + cn(4,5) + cn(2,5) + cn(3,5).at n=31A039903
- Partial sums of the sequence (A001097) of twin primes.at n=42A048598
- a(n) = a(1) + a(2) + ... + a(n-1) - a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the smallest integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 2, and a(3) = 3.at n=14A049909
- Least numbers m such that GCD of two consecutive values of cototients, i.e., gcd(cototient(m+1), cototient(m)) equals 2n - 1.at n=32A070017
- a(1) = 7 then the smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=28A083994
- Numbers n such that numerator(Bernoulli(2*n)/(2*n)) is different from numerator(Bernoulli(2*n)/(2*n*(2*n+1))).at n=25A090177
- Expansion of 1/((1-x)^2*(1-x^2)^2*(1-x^3)).at n=33A097701
- Semiprimes that are semiprimes turned upside-down.at n=40A119738
- Sum of the eighth powers of the first n Fibonacci numbers.at n=4A128697
- Let M(n) = maximal value of (n/k)^k over all k = 1, 2, ...; a(n) = round(M(n)).at n=23A139077
- Let M(n) = maximal value of (n/k)^k over all k = 1, 2, ...; a(n) = ceiling(M(n)).at n=23A139078
- a(n) = 2+2^n+3^n.at n=8A173657