9309
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
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 12960
- Proper Divisor Sum (Aliquot Sum)
- 3651
- 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
- 5936
- Möbius Function
- -1
- Radical
- 9309
- 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
- 153
- 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
- Eleven iterations of Reverse and Add are needed to reach a palindrome.at n=36A015992
- a(n) = s(1)*t(n) + s(2)*t(n-1) + ... + s(k)*t(n+1-k), where k = floor((n+1)/2), s = (natural numbers >= 3), t = A023532.at n=13A024314
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers >= 3), t = (Lucas numbers).at n=12A024877
- Digitally balanced numbers in both bases 2 and 3.at n=35A049361
- Numbers which need eleven 'Reverse and Add' steps to reach a palindrome.at n=34A065216
- Number of regions in regular n-gon which are quadrilaterals (4-gons) when all its diagonals are drawn.at n=25A067151
- Number of partitions of n such that there is exactly one part which occurs twice, while all other parts occur only once.at n=51A090858
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, -1), (1, -1, -1), (1, -1, 1), (1, 1, 1)}.at n=8A149516
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 1, -1), (1, -1, 1), (1, 0, 0), (1, 0, 1)}.at n=8A149906
- Number of nXnXn triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= 9.at n=6A166204
- Number of 6 X 6 X 6 triangular nonnegative integer arrays, symmetric under 120 degree rotation, with all sums of an element and its neighbors <= n.at n=9A166214
- A185128(n) is the a(n)-th triangular number.at n=45A185223
- Number of 0..n arrays x(0..8) of 9 elements with zero 4th differences.at n=43A200445
- Number of cyclotomic cosets of 3 mod 10^n.at n=34A220018
- Partial sums of A080670.at n=47A287881
- Start from the singleton set S = {n}, and unless 1 is already a member of S, generate on each iteration a new set where each odd number k is replaced by 3k+1, and each even number k is replaced by 3k+1 and k/2. a(n) is the size of the set after the first iteration which has produced 1 as a member.at n=58A290100
- Index of record values of A339082.at n=23A339173
- a(n) = [x^(n^4)] Product_{k=1..n} (x^(k^4) + 1/x^(k^4)).at n=33A368348
- Nonprime numbers k of the form 4*m+1 such that Sum_{j=0..k-1} 2^j * binomial(3*j, j) == 1 (mod k).at n=20A373747
- Number of closed knight's tours in the first 2n cells of a 5 X ceiling(2n/5) board.at n=8A383661