13328
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 30
- Divisor Sum
- 31806
- Proper Divisor Sum (Aliquot Sum)
- 18478
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5376
- Möbius Function
- 0
- Radical
- 238
- Omega Function (Ω)
- 7
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 32
- 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
- Coefficient of x^5 in expansion of (1 + x + x^2)^n.at n=13A000574
- Expansion of e.g.f. sec(arcsinh(x)*arcsin(x)), powers of x^4 only.at n=2A012608
- exp(arctanh(x)*arctan(x))=1+2/2!*x^2+12/4!*x^4+328/6!*x^6+13328/8!*x^8...at n=4A012727
- cosh(arctanh(x)*arctan(x)) = 1+12/4!*x^4+13328/8!*x^8+123701952/12!*x^12...at n=2A012735
- exp(arctanh(x)*tanh(x)) = 1+2/2!*x^2+12/4!*x^4+280/6!*x^6+13328/8!*x^8...at n=4A012754
- a(n) = n*(n + 1)*(3*n + 1).at n=16A027903
- Expansion of (theta_3(z)*theta_3(9z)+theta_2(z)*theta_2(9z))^4.at n=36A028604
- Number of partitions in parts not of the form 11k, 11k+1 or 11k-1. Also number of partitions with no part of size 1 and differences between parts at distance 4 are greater than 1.at n=48A035944
- Non-palindromic number and its reversal are both multiples of 17.at n=34A062915
- Number of (binary) bit strings of length n in which an odd length block of 0's is followed by an odd length block of 1's.at n=12A065495
- Sum of first n 8-almost primes.at n=12A086061
- Number of Motzkin paths of length n with no level steps at odd level.at n=14A090344
- Triangle read by rows: T(n,k) is the number of noncrossing forests with n vertices and k components (1<=k<=n).at n=30A094021
- Triangle read by rows: T(n,k) is the number of noncrossing forests with n vertices and k edges.at n=33A094040
- Triangle read by rows: T(n,k) is number of Motzkin paths of length n having k UH's, where U=(1,1), H=(1,0) (0<=k<=floor(n/3)).at n=40A114576
- Determinant of n X n matrix containing the first n^2 3-almost primes in increasing order.at n=3A118772
- a(n) = prime(n)^2 - prime(n^2). Commutator of (primes, squares) at n.at n=36A123914
- a(n) = gcd(n!, binomial(2n,n)).at n=27A135322
- a(n) = 512n + 16.at n=25A157475
- a(n) is the smallest number whose English name has the letter "t" in the n-th position, or -1 if no such number exists.at n=38A164792