12135
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19440
- Proper Divisor Sum (Aliquot Sum)
- 7305
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6464
- Möbius Function
- -1
- Radical
- 12135
- 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
- 249
- 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 series-reduced planted trees with n+9 nodes and 4 internal nodes.at n=29A001860
- a(n) = n*(27*n - 1)/2.at n=30A022284
- Every suffix prime and no 0 digits in base 6 (written in base 6).at n=46A024781
- Sequence is defined by property that binomial transform of (a0,a1,a2,a3,...) = (a0,a0,a0,a1,a1,a1,a2,a2,a2,a3,a3,a3,...).at n=16A051166
- Initial pile sizes that guarantee a win for player 2 in a variant of Fibonacci Nim where the players may not take one stone.at n=40A052492
- Numbers k such that k^2 * 2^k + 1 is prime.at n=22A058780
- "Fibonacci-digits": start with "11", append sum of first 2 digits to the preceding number, drop first digit.at n=10A093099
- G.f. satisfies: A(x) = 1/(1 + x*A(x^6)) and also the continued fraction: 1+x*A(x^7) = [1;1/x,1/x^6,1/x^36,1/x^216,...,1/x^(6^(n-1)),...].at n=61A101916
- Number of base 19 n-digit numbers with adjacent digits differing by one or less.at n=7A126373
- Number of partitions of n in which each odd part has odd multiplicity.at n=39A131942
- (L)-sieve transform of {1,4,7,10,...,3n-2,...} (A016777).at n=20A152009
- Smallest number m such that exactly n odd numbers can be seen as proper subsequences of m in decimal representation.at n=24A164766
- Triangle read by rows: T(n,k) is the number of cycle-up-down permutations of {1,2,...,n} having k fixed points (0 <= k <= n). A permutation is said to be cycle-up-down if it is a product of up-down cycles. A cycle (b(1), b(2), ...) is said to be up-down if, when written with its smallest element in the first position, it satisfies b(1) < b(2) > b(3) < ... .at n=45A186363
- Number of cycle-up-down permutations of {1,2,...,n} having no fixed points. A permutation is said to be cycle-up-down if it is a product of up-down cycles. A cycle (b(1), b(2), ...) is said to be up-down if, when written with its smallest element in the first position, it satisfies b(1)<b(2)>b(3)<... .at n=9A186364
- Number of n X 7 binary arrays without the pattern 0 1 diagonally, vertically or antidiagonally.at n=17A188864
- a(n)=n if n <= 3, otherwise a(n) = A007477(n-1) + A007477(n).at n=14A213705
- Numbers k such that either k^2*2^k-1 or k^2*2^k+1 is prime, but not both.at n=44A237759
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 197", based on the 5-celled von Neumann neighborhood.at n=25A270718
- Numbers k such that 18*10^k + 1 is prime.at n=19A282456
- Partial sums of A299894.at n=29A299895