2748
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
- 12
- Divisor Sum
- 6440
- Proper Divisor Sum (Aliquot Sum)
- 3692
- 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
- 912
- Möbius Function
- 0
- Radical
- 1374
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 40
- 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
- Low-temperature series in y = exp(2J/kT) for antiferromagnetic susceptibility for the Ising model on honeycomb structure.at n=10A002978
- Number of n-step spirals on hexagonal lattice.at n=15A006777
- Coordination sequence T3 for Zeolite Code MEI.at n=38A008148
- Coordination sequence T7 for Zeolite Code MTT.at n=32A008195
- Coordination sequence T1 for Zeolite Code -CLO.at n=46A009850
- Coordination sequence T3 for Zeolite Code RTH.at n=36A009895
- Partial sums of primes, if 1 is regarded as a prime (as it was until quite recently, see A008578).at n=38A014284
- Number of ordered positive integer solutions (m_1, m_2, ..., m_k) (for some k) to Sum_{i=1..k} m_i=n with |m_i-m_{i-1}| <= 1 for i = 2 ... k.at n=16A034297
- Numerators of continued fraction convergents to sqrt(571).at n=7A042094
- Numbers n such that string 8,3 occurs in the base 9 representation of n but not of n-1.at n=36A044326
- Numbers n such that string 4,8 occurs in the base 10 representation of n but not of n-1.at n=30A044380
- Numbers n such that string 8,3 occurs in the base 9 representation of n but not of n+1.at n=36A044707
- Numbers n such that string 4,8 occurs in the base 10 representation of n but not of n+1.at n=30A044761
- Numbers having, in base 14, (sum of even run lengths)=(sum of odd run lengths).at n=3A044885
- Numbers whose base-5 representation contains exactly one 1 and three 4's.at n=35A045254
- Numbers whose base-5 representation contains exactly one 3 and three 4's.at n=29A045299
- a(n) = T(n+1,n), array T given by A048201.at n=47A048204
- Pisot sequence L(6,7).at n=18A048585
- Pisot sequence L(7,9).at n=17A048589
- Discriminants of real quadratic number fields K with class number 2 such that the Hilbert class field of K is K(sqrt(3)).at n=18A052477