7318
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 10980
- Proper Divisor Sum (Aliquot Sum)
- 3662
- 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
- 3658
- Möbius Function
- 1
- Radical
- 7318
- 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
- 132
- Smith Number
- no
- 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
- Number of unlabeled mappings (or mapping patterns) from n points to themselves; number of unlabeled endofunctions.at n=10A001372
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Lucas numbers), t = (composite numbers).at n=19A025091
- 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 84.at n=21A031582
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 48 ones.at n=18A031816
- Denominators of continued fraction convergents to sqrt(605).at n=8A042161
- Numbers whose base-5 representation contains exactly two 2's and three 3's.at n=25A045273
- Sum of smallest parts of all partitions of n.at n=30A046746
- Numbers k such that k^4 == 1 (mod 5^5).at n=9A056102
- Indices of primes which remain prime if any one digit is deleted (leading zeros allowed).at n=40A084375
- Shadow of Pi.at n=37A110621
- Numbers whose trajectory under the Esucarys map ends at the fixed point 247.at n=7A129133
- a(n) = ceiling(n^3/3).at n=28A131477
- Average of Eulerian numbers (A008292) and Pascal's triangle (A007318): t(n,m) = (A008292(n,m) + A007318(n,m))/2.at n=38A141689
- Average of Eulerian numbers (A008292) and Pascal's triangle (A007318): t(n,m) = (A008292(n,m) + A007318(n,m))/2.at n=42A141689
- Triangular sequence defined by T(n, m) = Coefficients(q(x,n) + x^(n-2)*q(1/x,n))/4, where q(x, n) = d^2*P(x, n)/dx^2 and p(x, n)=(x-1)^(n+1)*Sum_{k>=0} ((-1)^(n + 1)*k^n)*x^(k-1).at n=21A154702
- Triangular sequence defined by T(n, m) = Coefficients(q(x,n) + x^(n-2)*q(1/x,n))/4, where q(x, n) = d^2*P(x, n)/dx^2 and p(x, n)=(x-1)^(n+1)*Sum_{k>=0} ((-1)^(n + 1)*k^n)*x^(k-1).at n=27A154702
- Numbers that are the product of two distinct primes and they are partial sum of products of two distinct primes.at n=21A168476
- Number of (w,x,y,z) with all terms in {1,...,n} and 3*w = x+y+z.at n=28A212069
- Triangular array read by rows. T(n,k) is the number of unlabeled functions on n nodes that have exactly k fixed points, n >= 0, 0 <= k <= n.at n=67A217897
- Numbers n such that n^2 + 1 is divisible by a 4th power.at n=24A218563