13227
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17640
- Proper Divisor Sum (Aliquot Sum)
- 4413
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8816
- Möbius Function
- 1
- Radical
- 13227
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 50
- 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
- a(0) = 1, a(n) = 25*n^2 + 2 for n > 0.at n=23A010015
- Number of 5-ary rooted trees with n nodes and height exactly 4.at n=19A036635
- Sums of p-th to the q-th prime where p and q are twin primes.at n=26A114379
- From the game of Quod: number of "squares" on an n X n array of points with the four corner points deleted.at n=18A124479
- a(n) = a(n-1) + a(n-2) + a(n-3) + a(n-4).at n=15A145028
- Constant term of the reduction by x^2 -> x+1 of the polynomial p(n,x) defined at Comments.at n=15A192975
- 1/4 the number of n X n 0..3 symmetric matrices with every element equal to zero, two or three horizontal and vertical neighbors.at n=3A211084
- a(0) = 16, after which, if a(n-1) = product_{k >= 1} (p_k)^(c_k), then a(n) = (1/2) * (1 + product_{k >= 1} (p_{k+1})^(c_k)), where p_k indicates the k-th prime, A000040(k).at n=43A246344
- Subword complexity of a the infinite word Prod_{i>=1} Prod_{j=1..i} a^j b^(i-j+1).at n=43A338761
- Triangle read by rows: row n consists of the n numbers k such that A075254(k) = A346378(n).at n=46A360637
- Semiprimes of the form k^2 + 2.at n=32A360739
- a(n) is the number of subsets of the first n primes whose sum is not a prime.at n=14A364535
- Number of integer partitions of n whose semi-sums do not cover an interval of positive integers.at n=35A367403