3186
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 7200
- Proper Divisor Sum (Aliquot Sum)
- 4014
- 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
- 1044
- Möbius Function
- 0
- Radical
- 354
- 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
- 123
- 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
- yes
- Odd
- no
Appears in sequences
- Heptagonal numbers (or 7-gonal numbers): n*(5*n-3)/2.at n=36A000566
- The game of Mousetrap with n cards (given n letters and n envelopes, how many ways are there to fill the envelopes so that at least one letter goes into its right envelope?).at n=7A002467
- Number of factorization patterns of polynomials of degree n over integers.at n=16A006171
- Expansion of 1/sqrt(1 - 12x + x^2).at n=3A006453
- Compositions: 6th column of A048004.at n=10A006980
- Energy function for hexagonal lattice.at n=8A007239
- Coordination sequence T2 for Zeolite Code MAZ.at n=39A008145
- Coordination sequence T2 for Zeolite Code MTN.at n=34A008187
- Coordination sequence T2 for Zeolite Code SGT.at n=35A008230
- Even heptagonal numbers (A000566).at n=18A014640
- Number of 4's in all partitions of n.at n=28A024788
- a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A025177.at n=7A025181
- Numbers k such that binomial(2k,k) is not divisible by 3, 5 or 7.at n=6A030979
- 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 56.at n=5A031554
- a(n) = (2*n+1)*(9*n+1).at n=13A033573
- Number of partitions of n with equal number of parts congruent to each of 2, 3 and 4 (mod 5).at n=46A035581
- Coordination sequence T3 for Zeolite Code AFN.at n=40A038401
- Coordination sequence T1 for Zeolite Code AFN.at n=40A038403
- a(n)=(s(n)+2)/8, where s(n)=n-th base 8 palindrome that starts with 6 (in base 8), written in decimal digits.at n=32A043070
- Numbers k such that the string 3,0 occurs in the base 9 representation of k but not of k-1.at n=44A044278