6669
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 11200
- Proper Divisor Sum (Aliquot Sum)
- 4531
- 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
- 3888
- Möbius Function
- 0
- Radical
- 741
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 3
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 31
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- 9 times the triangular numbers A000217.at n=38A027468
- a(n) = n^3 + (n+1)^3 + (n+2)^3.at n=12A027602
- Lucky numbers that are decimal concatenations of n with n + 3.at n=8A032653
- Numbers ending with '9' that are the difference of two positive cubes.at n=25A038864
- Number of partitions satisfying cn(1,5) + cn(4,5) <= cn(0,5).at n=42A039860
- The sequence e when b=[ 1,1,1,0,1,1,... ].at n=55A042957
- Numbers having three 6's in base 10.at n=26A043515
- Numbers whose base-9 representation has exactly 5 runs.at n=16A043634
- Numbers k that divide 7^k + 2^k.at n=27A045580
- Beastly (or hateful) numbers: numbers containing the string 666 in their decimal expansion.at n=15A051003
- Values of e, the lesser key or generating number for Pythagorean triangles in which S (the odd short leg) and U (the hypotenuse) are twin primes.at n=29A051892
- Periodic points under the map A053392 that adds consecutive pairs of digits and concatenates them.at n=24A053393
- Number of obtuse triangles made from vertices of a regular n-gon.at n=39A060423
- Numbers k such that gcd(k, reverse(k)) = 27 = 3^3, where reverse(x) = A004086(x).at n=13A072016
- a(n) = floor(T(n+1)!*T(n-1)!/(T(n)!)^2), where T(n) = n(n+1)/2 = the n-th triangular number.at n=41A077539
- Orchard crossing number of complete bipartite graph K_{1,n}.at n=38A080838
- Number of partitions of n such that the set of even parts has only one element.at n=39A090867
- a(n) = (5/6)*n^3+(5/2)*n^2+(8/3)*n.at n=19A092185
- Structured tetrakis hexahedral numbers (vertex structure 5).at n=12A100174
- 5-almost primes with semiprime digits (digits 4, 6, 9 only).at n=8A111697