7528
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14130
- Proper Divisor Sum (Aliquot Sum)
- 6602
- 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
- 3760
- Möbius Function
- 0
- Radical
- 1882
- Omega Function (Ω)
- 4
- 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
- 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 inequivalent ways of dissecting a regular (n+2)-gon into n triangles by n-1 non-intersecting diagonals under rotations and reflections; also the number of (unlabeled) maximal outerplanar graphs on n+2 vertices.at n=11A000207
- Number of secondary alcohols (alkanols or alkyl alcohols C_n H_{2n+1} OH) with n carbon atoms.at n=13A000599
- Expansion of 1/(1 - x^2 - x^3 - x^4) = 1/((1 + x)*(1 - x - x^3)).at n=26A013979
- 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 43.at n=20A031541
- Numbers whose set of base-12 digits is {3,4}.at n=27A032836
- Let (u1,u2) be successive untouchable numbers such that phi(u1) = phi(u2); sequence gives values of u2.at n=22A048190
- Expansion of 1/(1-x+x^2-2*x^3).at n=32A077951
- Expansion of 1/(1+x+x^2+2*x^3).at n=32A077976
- Number of ways to represent n as a+b*(c+d*(e+f*(...x+y*(z)...))) in positive integers.at n=12A084978
- Expansion of g.f.: (1-x^2-x^3)/( (1+x)*(1-x-x^3) ).at n=30A107458
- Expansion of (-16-7*x+6*x^2+28*x^3+8*x^4) / ((x-1)*(x^2+x+1)*(4*x^2-8*x+1)).at n=3A110274
- Positive numbers that are not the sum of two squares and a positive Fibonacci number.at n=19A115176
- Inverse Moebius transform of the shifted tetrahedral numbers.at n=32A116963
- Integer part of Gauss's Arithmetic-Geometric Mean M(1,n^3).at n=38A127759
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k base pyramids.at n=58A129165
- a(n) = 8 - 12*n + 5*n^2.at n=39A145995
- G.f.: A(x) = exp( Sum_{n>=1} (3^n + 1)^n * x^n/n ), a power series in x with integer coefficients.at n=3A155204
- Number of n X n arrays of squares of integers with every 3X3 subblock summing to 6.at n=2A159206
- Number of n X n arrays of squares of integers with every (n-2)X(n-2) subblock summing to 6.at n=1A159365
- Number of nondecreasing arrangements of n+2 numbers in 0..3 with each number being the sum mod 4 of two others.at n=31A183906