6623
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 6840
- Proper Divisor Sum (Aliquot Sum)
- 217
- 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
- 6408
- Möbius Function
- 1
- Radical
- 6623
- 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
- 168
- 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
- Number of coprime chains with largest member prime(n).at n=28A003140
- a(n) = floor(n*(n - 1)*(n - 2)/31).at n=60A011913
- Divide natural numbers in groups with prime(n) elements and add together.at n=11A034956
- Numbers k such that the product of the digits of k is equal to the sum of the prime factors of k, counted with multiplicity.at n=23A065774
- Numbers n such that the sum of the prime factors of n equals the product of the digits of n.at n=18A067173
- Centered heptagonal numbers.at n=43A069099
- Numbers k such that phi(k) divides sigma(k+1) - sigma(k).at n=30A072611
- Fibonacci sequence beginning 12, 67.at n=11A091074
- Numbers k such that the k-th and (k+1)-th primes have the same sum of squares of digits.at n=27A109182
- First differences of A115855.at n=16A115856
- n times pi(n) is a palindrome, where pi(n) = PrimePi(n) = A000720(n).at n=27A116054
- Numerator of partial sums for a series of (17/18)*Zeta(4) = (17/1680)*Pi^4.at n=2A130416
- Numbers k such that abundance(k) + abundance(k+1) = 2.at n=7A137205
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (-1, 1, 1), (0, 1, 0), (1, -1, 1), (1, 1, -1)}.at n=8A148495
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 0), (-1, 0, 1), (0, 1, -1), (1, -1, 0), (1, 1, 1)}.at n=7A149775
- a(n) = 288*n - 1.at n=22A157997
- a(n) = 46*n^2 - 1.at n=11A158634
- Base-10 encoding of the Spanish name of n with one digit per letter as on a touch-tone telephone.at n=11A165948
- Numbers n such that the digits of sigma(n) are exactly the same (albeit in different order) as the digits of phi(n), in base 10.at n=13A175795
- Number of "ON" cells at n-th stage of three-dimensional version of the cellular automaton A183060 using cubes.at n=39A186410