3666
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 8064
- Proper Divisor Sum (Aliquot Sum)
- 4398
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1104
- Möbius Function
- 1
- Radical
- 3666
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- 43
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- 5th-order maximal independent sets in cycle graph.at n=46A007388
- a(n) = floor(n*(n+2)*(2*n-1)/8).at n=23A007518
- Coordination sequence T1 for Zeolite Code AFG.at n=42A008012
- Coordination sequence T1 for Zeolite Code LOS.at n=42A008132
- Coordination sequence T7 for Zeolite Code TER.at n=41A016439
- Magic numbers: atoms with full shells containing any of these numbers of electrons are considered electronically stable.at n=25A018227
- Expansion of 1/((1-2*x)*(1-5*x)*(1-7*x)*(1-8*x)).at n=3A025992
- (d(n)-r(n))/5, where d = A008778 and r is the periodic sequence with fundamental period (0,3,1,0,1).at n=44A026053
- a(n)=(s(n)+1)/8, where s(n)=n-th base 8 palindrome that starts with 7.at n=28A043071
- Numbers having three 6's in base 10.at n=3A043515
- Beastly (or hateful) numbers: numbers containing the string 666 in their decimal expansion.at n=3A051003
- A simple grammar: pairs of cycles of sequences.at n=13A052821
- n*M127 - 1 is prime, where M127 = 2^127 - 1.at n=33A057441
- a(n) = least value such that sequence increases and pairwise differences are unique.at n=45A058336
- B-trees of order 5 with n labeled leaves.at n=17A058521
- a(n) = (n/2)*(n + 1)*(3*n + 11).at n=11A059997
- Unitary untouchable numbers: us(x) = n has no solution where us(x) (A063919) is the sum of the proper unitary divisors of x.at n=24A063948
- Numbers n such that phi(n) = phi(n-1) - phi(n-2).at n=6A066231
- For even n>=4, let f(n)=A066285(n/2) be the minimal difference between primes p and q whose sum is n. This sequence contains the successive maxima of f.at n=42A066286
- Number of ways to tile a 4 X n room with 1x2 Tatami mats. At most 3 Tatami mats may meet at a point.at n=45A068923