8041
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9504
- Proper Divisor Sum (Aliquot Sum)
- 1463
- 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
- 6720
- Möbius Function
- -1
- Radical
- 8041
- Omega Function (Ω)
- 3
- 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
- 96
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Pseudoprimes to base 42.at n=23A020170
- Pseudoprimes to base 50.at n=40A020178
- Pseudoprimes to base 87.at n=40A020215
- Strong pseudoprimes to base 50.at n=8A020276
- a(n) = Sum_{k=floor((n+1)/2)..n} T(k,n-k); i.e., a(n) is the n-th diagonal sum of left-justified array T given by A026998.at n=21A027010
- Number of partitions of n that do not contain 4 as a part.at n=35A027338
- (s(n)+2)/10, where s(n)=n-th base 10 palindrome that starts with 8.at n=26A043087
- Numbers having four 1's in base 6.at n=33A043376
- Row/column pre-periods of Sprague-Grundy values of Wythoff's Game.at n=37A046874
- Number of 3 X 3 matrices with elements from [0,...,(n-1)] satisfying the condition that the middle element of each row or column is the difference of the two end elements (in absolute value).at n=10A058333
- a(n) = A051201(n^2).at n=40A078163
- Take the list t(n,0) = {1,...,n}; denote by t(n,j) this list after rotating to left (or right) by j positions. Calculate inner product of t(n,0) and t(n,j) and denote the value by s(n,j). Compute this inner product for all j = 1..n and choose the smallest. This is a(n).at n=32A088003
- Iccanobirt numbers (8 of 15): a(n) = R(a(n-1) + a(n-2) + a(n-3)), where R is the digit reversal function A004086.at n=15A102118
- Row sums of triangle A135858.at n=20A135859
- Binomial transform of [1, 3, 7, 0, 0, 0, ...].at n=48A140063
- Numbers that have an "a" in the middle of their names in Spanish.at n=33A160775
- Least of 4 consecutive integers such that their product +-5 are primes.at n=43A174244
- Number of 0..n arrays x(0..3) of 4 elements without any two consecutive increases or two consecutive decreases.at n=9A200839
- Number of (n+1)X(n+1) -6..6 symmetric matrices with every 2X2 subblock having sum zero and one or three distinct values.at n=7A211255
- Numbers which are the roots of distinct not-previously-encountered side-trees ("tendrils") sprouting from the side of the infinite beanstalk (see A213730).at n=23A218612