4918
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 7380
- Proper Divisor Sum (Aliquot Sum)
- 2462
- 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
- 2458
- Möbius Function
- 1
- Radical
- 4918
- 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
- 103
- Smith Number
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = 1 + n/2 + 9*n^2/2.at n=33A006137
- sec(tan(x)+sin(x))=1+4/2!*x^2+88/4!*x^4+4918/6!*x^6+512840/8!*x^8...at n=3A012946
- 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 70.at n=1A031568
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 46 ones.at n=9A031814
- Conjecturally, a power of 2 written in base 3 cannot have this many 0's.at n=42A036462
- Numbers having three 6's in base 9.at n=22A043479
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), with a(1) = a(2) = 1 and a(3) = 4.at n=12A049944
- Closed 3-dimensional ball numbers (version 2): a(n)= number of integer points (i,j,k) contained in a closed ball of diameter n, centered at (1/2,0,0).at n=21A053593
- Consecutive terms of A065966 which are also consecutive integers.at n=15A065976
- 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=35A077539
- a(n) = n^3 + 5.at n=17A084381
- Prime productive numbers m: Let the digits of m be abcd. Then the numbers bcd*a+1, cd*ab+1, d*abc+1, abcd+1 etc. are all primes. If m is a k-digit number it produces k such primes.at n=51A089395
- Numbers k such that 3*R_k + 4 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=12A099411
- Number of inner dual graphs of planar polyhexes with n hexagons.at n=10A108071
- Smaller of two consecutive semiprimes with the same digital root.at n=30A118699
- Triangle, read by rows, where T(n,k) = T(n-1,k-1) + T(n-1,k) + T(n-1,k+1) for n>=k>=1, with T(0,0) = 1, T(n,n) = T(n,0) + T(n-1,n-1) for n>=1; T(n,k)=0 when n<k or k<0.at n=47A121400
- Number of isomeric aza-benzenoids with three nitrogen atoms and n hexagons.at n=4A121951
- Number of diamond-free Berge perfect graphs on n nodes.at n=8A123420
- a(n) = Sum of all numbers of divisors of all numbers < (n+1)^2.at n=25A168011
- G.f.: A(x) = 1/(1 - x*(1+x)/(1 - x^2*(1+x)/(1 - x^3*(1+x)/(1 - x^4*(1+x)/(1 - ...))))), a continued fraction.at n=12A193021