9615
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 15408
- Proper Divisor Sum (Aliquot Sum)
- 5793
- 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
- 5120
- Möbius Function
- -1
- Radical
- 9615
- 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
- 122
- 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
- a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A025177.at n=8A025181
- (1/4 - 1/6 + ... + d/c(n))*LCM{4, 6, ..., c(n)}, where d = (-1)^(n-1), c(n) = n-th composite number.at n=12A025546
- Numbers k that divide the (left) concatenation of all numbers <= k written in base 11 (most significant digit on left).at n=20A029480
- Euler transform of Thue-Morse sequence A001285.at n=22A029877
- Exactly 5 digits from {1,2,3,4,5,6,7,8,9} can precede a(n) to form a lucky number.at n=33A032701
- Number of points in N^n of norm <= 3.at n=11A055418
- Squarefree products of factors of Fermat numbers (A023394).at n=16A094358
- Start with 1057 and repeatedly reverse the digits and add 2 to get the next term.at n=13A120215
- Numbers n such that n^3 - 4 and n^3 + 4 are prime.at n=36A161589
- Partial sums of A006431.at n=23A178419
- Super anti-perfect numbers.at n=6A192275
- Let sigma*_m (n) be result of applying sum of anti-divisors m times to n; call n (m,k)-anti-perfect if sigma*_m (n) = k*n; sequence gives the (2,k)-anti-perfect numbers.at n=24A229860
- Number of length n+2 0..7 arrays with the sum of the maximum minus the median of adjacent triples multiplied by some arrangement of +-1 equal to zero.at n=2A251934
- T(n,k)=Number of length n+2 0..k arrays with the sum of the maximum minus the median of adjacent triples multiplied by some arrangement of +-1 equal to zero.at n=38A251935
- Number of length 3+2 0..n arrays with the sum of the maximum minus the median of adjacent triples multiplied by some arrangement of +-1 equal to zero.at n=6A251937
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 113", based on the 5-celled von Neumann neighborhood.at n=23A270179
- Number of set partitions of [n] such that all absolute differences between least elements of consecutive blocks and between consecutive elements within the blocks are not larger than three.at n=10A287582
- a(n) = cardinality of a certain set of natural numbers defined using A117818.at n=21A292772
- Numbers k such that q = 2^k - 2^m + 1 is prime, where m = A270096(k).at n=53A307625
- a(n) is the first component x of the distance vector (x,y) in an oblique 120-degree coordinate system, 0 <= y <= x, between two nodes of an infinite triangular lattice of one-ohm resistors, such that the resistance R between the two nodes is as close as possible to n ohms, i.e., abs(R - n) is minimized. y is A356204(n).at n=2A356203