13663
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 14728
- Proper Divisor Sum (Aliquot Sum)
- 1065
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12600
- Möbius Function
- 1
- Radical
- 13663
- Omega Function (Ω)
- 2
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 45
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Numbers whose base-4 representation contains exactly four 1's and three 3's.at n=20A045132
- Largest eigenvalue, rounded to the nearest integer, of a rank n matrix of 1..n^2 filled successively along rows.at n=29A072333
- Square root of n has the same nonzero digit in each of the first 4 places to the right of the decimal point.at n=5A073585
- Index of the first occurrence of A019565(2n-1) in sequence A103790.at n=37A103791
- a(n) = n^3 - 7*n + 7.at n=23A106734
- Start with 1 and repeatedly reverse the digits and add 66 to get the next term.at n=18A118200
- a(n) = 81*n^2 - 2*n.at n=12A157507
- Snub dodecahedron with faces of centered polygons.at n=6A193249
- G.f.: A(x) = Sum_{n>=0} x^n * A(x)^A006068(n) where A006068 forms the inverse permutation of the binary Gray code numbers (A003188).at n=9A204686
- E.g.f. satisfies: A(x) = exp( x + Integral Integral A(x)^3 dx dx ).at n=7A234239
- Triangle read by rows: T(n,k) is the number of bargraphs of semiperimeter n having width k (n>=2, k>=1).at n=71A271942
- Numbers k such that k![12]-2 is prime, where k![12] is the twelve-fold multifactorial.at n=47A284132
- Partial sums of icosahedral numbers (A006564).at n=11A302560
- Number of pairs (lambda,mu) of partitions lambda of n and mu of three with mu <= lambda (by diagram containment).at n=26A303853
- Array read by ascending antidiagonals: T(n, k) is the number of n-core partitions with k corners.at n=60A355010
- Numbers k such that 30*k - 1, 30*k + 1, 30*k^2 - 1 and 30*k^2 + 1 are all prime.at n=22A359184
- Number of finite sets of positive integers whose right half (exclusive) sums to n.at n=42A360954
- a(n) is the smallest nonnegative integer such that the sum of any four ordered terms a(k), k<=n (repetitions allowed), is unique.at n=12A365300