8220
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 23184
- Proper Divisor Sum (Aliquot Sum)
- 14964
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2176
- Möbius Function
- 0
- Radical
- 4110
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 4
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
- 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
- A generalized partition function.at n=15A002601
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MON = Montesommaite (K,Na)9[ Al9Si23O64 ] . 10 H2O.at n=12A019178
- Maximal coefficient of Product_{k<=n} (1 + x^k). Number of solutions to +- 1 +- 2 +- 3 +- ... +- n = 0 or 1.at n=19A025591
- a(n) = Sum_{i=0..floor(n/2)} T(2i,n-2i), array T as in A048149.at n=30A049714
- Number of labeled semi-strong digraphs on n nodes with an even number of components.at n=4A054950
- Number of 6-element ordered T_0-antichains on an unlabeled n-set; T_1-hypergraphs on 6 labeled nodes with n (not necessarily empty) distinct hyperedges (n=0,1,...,64).at n=5A059049
- Number of solutions to +- 1 +- 2 +- 3 +- ... +- n = 0.at n=19A063865
- Number of solutions to +- 1 +- 2 +- 3 +- ... +- n = 0 or +- 1.at n=19A063867
- Product of numerator and denominator of the n-th harmonic number, 1 + 1/2 + 1/3 +...+ 1/n.at n=4A064167
- Trisection of A007294.at n=33A073470
- First differences are formed by interleaving {2^k - 1, k = 1, 2, 3, ...} and {11*k, k = 5, 4, 3, ...}.at n=23A086848
- a(n) is a non-palindromic composite located between twin primes whose reverse, which is less than it, is also located between twin primes.at n=10A103741
- Average of twin-prime pairs for pairs that are expressible as the sum of two triangular numbers.at n=20A117313
- A063865(4n-3).at n=4A123117
- Numbers n that raised to the powers from 1 to k (with k>=1) are multiple of the sum of their digits (n raised to k+1 must not be a multiple). Case k=8.at n=14A135193
- Defined in comments.at n=7A141411
- a(n) = 216*n + 12.at n=37A154519
- Numbers k such that k-1, k+1, and k^2-k-1 are primes.at n=29A154666
- Averages of twin prime pairs which are a sum of averages of two consecutive twin prime pairs.at n=22A160916
- Number of reduced 3 X 3 magilatin squares with magic sum n.at n=19A174020