8227
domain: N
Properties
Digital Properties
- Digit Count
- 4
- 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
- 8680
- Proper Divisor Sum (Aliquot Sum)
- 453
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7776
- Möbius Function
- 1
- Radical
- 8227
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 39
- 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
- Number of partitions of n if there are two kinds of 1's and two kinds of 2's.at n=21A000097
- a(n) = floor(n*(n-1)*(n-2)/9).at n=43A011891
- a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p diving [ A*a(n)+B ] and p=2, A=2.00013, B=3.0.at n=30A029580
- 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 89.at n=30A031587
- Numbers whose base-4 representation contains exactly four 0's and no 1's.at n=27A045033
- Numbers whose base-4 representation contains exactly four 0's and two 2's.at n=27A045059
- A Diaconis-Mosteller approximation to the Birthday problem function.at n=37A050255
- a(n) = floor[X/Y] where X = the concatenation of the first n even numbers in increasing order and Y = their sum.at n=4A067121
- Integers which are exactly the concatenation of the first m even numbers (A019520) divided by their sum (A002378 = m^2+m).at n=2A072724
- Numbers k such that phi(k) is a perfect 5th power.at n=22A078165
- Recursive binary interleaving code for rooted plane binary trees, as ordered by A014486.at n=13A082856
- a(n) = floor(C(n+6,6)/C(n+2,2)).at n=37A084626
- a(0) = 1, then (for n>0) a(n) = floor[(e + 1/e)*a(n-1) - a(n-2)].at n=9A085560
- Triangle read by rows: colored polyominoes. For n >= 1, 1 <= k <= n, T(n, k) is the number of k-colored n-celled polyominoes, counted up to rotation, reflection and permutation of the colors. Adjacent cells must be different colors. T(n, k) counts only polyominoes that include all k colors.at n=24A088972
- a(n) = 2^(n+1) - 1 + 3*n.at n=12A131833
- Size of the reduced Groebner basis of the ideal < x*y(1)^vj(1)*...*y(n-2)^vj(n-2) - z(j) : j=1,2,...,m >, where vj is the j-th extreme n-breakable vector, m=A141348(n), w.r.t. the degree of x and graded reverse lexicographic ordering of the variables y(1), ..., y(n-2), z(1), ..., z(m).at n=6A141349
- a(n) = 242*n - 1.at n=33A157961
- a(n) = 484*n - 1.at n=16A158330
- a(n) = 68*n^2 - 1.at n=10A158730
- The non-common part of the larger number of an amicable pair.at n=37A180327