13312
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 22
- Divisor Sum
- 28658
- Proper Divisor Sum (Aliquot Sum)
- 15346
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6144
- Möbius Function
- 0
- Radical
- 26
- Omega Function (Ω)
- 11
- 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
- 19
- 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
- a(n) = (n+2)*2^(n-1).at n=11A001792
- Denominators of Taylor series expansion of arcsin(x). Also arises from arccos(x), arccsc(x), arcsec(x), arcsinh(x).at n=6A002595
- a(n) = 13*2^n.at n=10A005029
- Related to self-avoiding walks on square lattice.at n=7A006816
- E.g.f. tanh(sin(x)*sin(x)) (even powers only).at n=4A009801
- Expansion of e.g.f. arctan(sin(x)*sin(x)), even powers only.at n=3A012297
- Duplicate of A009801.at n=3A012300
- Expansion of (theta_3(z)*theta_3(23z)+theta_2(z)*theta_2(23z))^4.at n=31A028660
- 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 57.at n=35A031555
- Composite numbers k such that digits in k and in juxtaposition of prime factors of k are the same (apart from multiplicity).at n=31A035141
- Numbers ending with '2' that are the difference of two positive cubes.at n=32A038857
- a(n) = Sum_{k=0..floor(n/2)} k*binomial(n,2*k) = floor(n*2^(n-3)).at n=13A049610
- a(n) = Sum_{d|n, n/d=1 mod 4} d^3 - Sum_{d|n, n/d=3 mod 4} d^3.at n=23A050471
- a(n) = 2^(n-1)*(3*n-4).at n=10A053565
- a(n) is the smallest number such that a(n)+1 is a prime and the largest power of 2 which divides it is 2^n.at n=10A057777
- 11-almost primes (generalization of semiprimes).at n=12A069272
- Triangle in which n-th row gives ascending sequence of numbers derived from the (3x+1) problem, beginning with n. Numbers in one row share the same number of iteration steps required to reach the value of '1' when applying the (3x+1) algorithm. Each row terminates with a power of 2.at n=22A069323
- Let x(1)=1, x(n+1) = (4/3)*x(n) - floor((4/3)*x(n)); then a(n)=x(n)*3^n.at n=9A073533
- a(n) is the smallest x such that the quotient d(x)/d(x+1) equals n, where d = A000005.at n=10A080372
- Number of 4 X n binary matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (10;0) and (01;1).at n=6A100313