13671
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 23712
- Proper Divisor Sum (Aliquot Sum)
- 10041
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7560
- Möbius Function
- 0
- Radical
- 651
- 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
- 120
- 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
- no
- Odd
- yes
Appears in sequences
- a(n) = a(n-1) + a(n - 1 - number of even terms so far).at n=45A006336
- a(n) = (2*n - 11)*n^2.at n=21A015245
- a(n) is least k such that k and 5k are anagrams in base n (written in base 10).at n=16A023097
- Numbers in which all pairs of consecutive base-5 digits differ by 3.at n=18A033076
- Numbers whose base-5 representation contains exactly three 1's and three 4's.at n=14A045262
- Number of nonempty subsets of {1,2,...,n} in which exactly 1/3 of the elements are <= (n-2)/2.at n=16A047183
- House numbers (version 2): a(n) = (n+1)^3 + (n+1)*Sum_{i=0..n} i.at n=20A050509
- Indices of primes in sequence defined by A(0) = 77, A(n) = 10*A(n-1) - 23 for n > 0.at n=6A056258
- Positive numbers whose product of digits is 7 times their sum.at n=39A062384
- a(n) = (2*n - 1)*(11*n^2 - 11*n + 6)/6.at n=15A063492
- a(n) = 9*(n-2)^2*(n^2-2*n-1)/2.at n=7A064199
- Sum of squares of divisors of square numbers.at n=9A065827
- Numbers k such that N*2^k + 1 is prime where N = 9999999999999999999999988888888888888888887777777777777777766666666666665555555555544444443333322211.at n=19A098467
- Integers that are Rhonda numbers to more than one base.at n=25A100988
- Number of partitions of n with no part larger than n/2. Also partitions of n into n/2 or fewer parts.at n=35A110618
- A triangular sequence: T(n,m) = t1(n,m) + t1(n,n-m) where t1(n,m) = -Sum_{j=0..m+1} (-1)^j * t0(n + 2, j) * (m - j + 1)^(n + 1) and t0(n,m) = Sum_{j=0..m+1} (-1)^j * binomial(n + 2, j) * (m - j + 1)^(n + 1).at n=13A154869
- A triangular sequence: T(n,m) = t1(n,m) + t1(n,n-m) where t1(n,m) = -Sum_{j=0..m+1} (-1)^j * t0(n + 2, j) * (m - j + 1)^(n + 1) and t0(n,m) = Sum_{j=0..m+1} (-1)^j * binomial(n + 2, j) * (m - j + 1)^(n + 1).at n=11A154869
- a(n) = 169*n^2 - 2*n.at n=8A158218
- Number of binary strings of length n with no substrings equal to 0011 0101 or 0110.at n=16A164503
- Totally multiplicative sequence with a(p) = 10p+1 for prime p.at n=11A166668