7640
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 17280
- Proper Divisor Sum (Aliquot Sum)
- 9640
- 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
- 3040
- Möbius Function
- 0
- Radical
- 1910
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 31
- 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
- Expansion of Product_{k>=1} (1 - x^k)^16.at n=28A000739
- Rabbytes: group eight successive Fibonacci numbers in binary and translate to decimal.at n=6A006224
- Number of partitions satisfying (cn(0,5) <= cn(1,5) = cn(4,5) and cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5)).at n=52A036819
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 77 ).at n=34A063350
- a(n) = n*binomial(2n, n) - 4^n.at n=7A068554
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having height of the last peak equal to k (1 <= k <= n).at n=38A128745
- Table of expansion coefficients [x^m] of the Rayleigh polynomial of index 2n.at n=19A158616
- Antidiagonal sums of A163280.at n=22A163983
- First of two consecutive numbers with at least one 3 in their prime signature.at n=37A176313
- Unlabeled super-Catalan numbers: patterns of nonintersecting chords joining unlabeled points on a circle.at n=8A183757
- G.f. A(x) satisfies A(x) = 1+x + x^2*[d/dx A(x)^2].at n=6A185183
- Triangle of coefficients of polynomials v(n,x) jointly generated with A208761; see the Formula section.at n=40A208762
- Number of 2 X 2 matrices with all elements in {0,1,...,n} and determinant >=n.at n=11A210366
- Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having two, three, four, five or six distinct values for every i,j,k<=n.at n=5A211580
- Numbers k such that 19*k+1 is a square.at n=40A219396
- Number of partitions p of n such that the number of parts having multiplicity 1 is not a part and max(p) - min(p) is a part.at n=46A241448
- Expansion of f(x^2)^2 / f(-x) in powers of x where f() is a Ramanujan theta function.at n=31A260163
- Number of trapezoidal words of length n.at n=36A260881
- Expansion of f(-x)^8 * Q(x) in powers of x where f() is a Ramanujan theta function and Q() is a Ramanujan Lambert series.at n=14A277076
- Number of 3 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.at n=11A281207