9105
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 14592
- Proper Divisor Sum (Aliquot Sum)
- 5487
- 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
- 4848
- Möbius Function
- -1
- Radical
- 9105
- 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
- yes
- 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
- Number of partitions of n into parts not of the form 15k, 15k+2 or 15k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 6 are greater than 1.at n=39A035956
- Rounded total surface area of a regular dodecahedron with edge length n.at n=21A071397
- Number of distinct lines through the origin in 4-dimensional cube of side length n.at n=9A090026
- Numbers k such that p(k), p(k)+6, p(k)+12, p(k)+18 are consecutive primes, where p(k) denotes k-th prime.at n=34A090832
- Numbers n such that if p=prime(n), then p, p+6, p+12, p+18 are consecutive primes with p=6*k+5 for some k, where prime(n) denotes n-th prime.at n=17A090835
- Starting from the standard 12 against 12 starting position in checkers, the sequence gives the number of distinct positions that can arise after n moves.at n=6A133047
- a(n) is the smallest natural number we cannot obtain from n, n+1, n+2, n+3, n+4, n+5, n+6 and the operators +, -, *, /, using each number only once.at n=6A143191
- a(n+1) = 4*a(n) - n.at n=7A164044
- a(n) = 5*2^n/9 + 1/4 + (-1)^n*(n/6 + 7/36).at n=14A172416
- Number of nondecreasing arrangements of n numbers in -3..3 with sum zero and sum of squares less than n*12/3.at n=24A183929
- The number of closed normal form lambda calculus terms of size n, where size(lambda x.M)=2+size(M), size(M N)=2+size(M)+size(N), and size(V)=1+i for a variable V bound by the i-th enclosing lambda (corresponding to a binary encoding).at n=27A195691
- Integers m such that m^3 is the sum of two or more consecutive integer squares.at n=14A212018
- Smallest number k such that sopf(k)/digsum(k) = prime(n) where sopf(k) is the sum of the distinct primes dividing k and digsum(k) the sum of digits of k.at n=12A241049
- Composite numbers n such that E(n+1)+1 is divisible by n, where E(n) is the n-th Euler number (A122045).at n=14A287934
- Number n such that the whole sequence of the first n terms of A293700 is a palindrome.at n=40A294923
- Harary index of the n X n white bishop graph.at n=17A296200
- Maximum value of the cyclic convolution of first n primes with themselves.at n=14A299111
- Coordination sequence for "tea" 3D uniform tiling.at n=34A299285
- Number of integer partitions of n whose parts are all equal or whose distinct parts are pairwise coprime.at n=44A304712
- a(n) = T(n, 4) with T(n, k) = Sum_{d|k} phi(d)*binomial(n - 1 + k/d, k/d).at n=20A327032