7088
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 10
- Divisor Sum
- 13764
- Proper Divisor Sum (Aliquot Sum)
- 6676
- 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
- 3536
- Möbius Function
- 0
- Radical
- 886
- Omega Function (Ω)
- 5
- 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
- 57
- 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
- Number of partitions satisfying (cn(1,5) = cn(4,5) and cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5)).at n=48A036814
- Position of n! in A025487.at n=15A098718
- Triangle read by rows: T(n,k) is the number of binary trees (each vertex has 0, or 1 left, or 1 right, or 2 children) with k edges and all leaves at level n.at n=40A106375
- Let r be the matrix {{1,1},{0,1}} and b={{1,0},{1,0}}. Let A be the semigroup generated by r and b. a(n) is the number of words of length n in A.at n=33A121946
- Records in A018892.at n=43A126097
- Indices of 4's in A090822.at n=31A157107
- Triangle T(n,r), read by rows, where the r-th column is expansion of A(x)^r, with A(x) = x * (x+1) * (2*x^4+4*x^3-2*x+1) * (x^4+2*x^3-x+1) / (x^2+x-1)^6.at n=62A187055
- Number of nondecreasing arrangements of 10 numbers in 0..n with the last equal to n and each after the second equal to the sum of one or two of the preceding four.at n=28A189333
- Triangle of coefficients of polynomials v(n,x) jointly generated with A209753; see the Formula section.at n=49A209754
- a(n) is the first occurrence of n in sequence A209266.at n=23A211389
- Numbers equal to the Euler totient function of their arithmetic derivative: k = phi(k').at n=36A217715
- Number of happy numbers without zeros and with digits in nondecreasing order <= 10^n.at n=9A219667
- Total sum of parts of multiplicity 6 in all partitions of n.at n=34A222734
- Total number of F shapes in all tilings of a 5 X n rectangle with pentominoes of any shape.at n=6A247735
- Number of times a multiple of four is encountered when iterating from 2^(n+1)-2 to (2^n)-2 with the map x -> x - (number of runs in binary representation of x).at n=17A255125
- Numbers k such that k^2 + 1 = p*q*r*s where p,q,r,s are distinct primes and the sum p+q+r+s is a perfect square.at n=32A261530
- Union of all unique coefficients of all powers of the g.f. A(x) of this sequence, starting with A(0)=2 and A'(0)=3.at n=53A262975
- Numbers k such that the number of divisors of k+2 divides k and the number of divisors of k divides k+2.at n=40A268037
- a(n) begins the first chain of 9 consecutive positive integers of h-values with symmetrical gaps about the center, where h(k) is the length of the finite sequence k, f(k), f(f(k)), ...., 1 in the Collatz (or 3x + 1) problem.at n=28A268288
- a(n) = (1/2)*A291730(n).at n=8A291731