12727
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 15120
- Proper Divisor Sum (Aliquot Sum)
- 2393
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10560
- Möbius Function
- -1
- Radical
- 12727
- 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
- 81
- 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
- Coefficient of x^6 in expansion of (1+x+x^2)^n.at n=10A005714
- a(n) = T(2*n+1,n), with T given by A027907.at n=6A027911
- T(n,[ n/2 ]), T given by A027907.at n=13A027913
- Number of partitions satisfying cn(0,5) + cn(2,5) + cn(3,5) <= cn(1,5) + cn(4,5).at n=36A039879
- Distinct odd numbers in the numerators of the 1/5-Pascal triangle (by row).at n=38A046624
- Distinct odd numbers in writing first numerator and then denominator of each element to the right of the central elements of the 1/5-Pascal triangle (by row).at n=33A046628
- Numbers k such that 2^k + 9 is prime.at n=42A057196
- Triangular Kaprekar-like numbers: numbers k such that the base-10 representation of T(k) = k*(k+1)/2 is the concatenation of two numbers x and y such that x + y = k.at n=31A110939
- Limiting sequence of second differences of certain Poincaré series [or Poincare series] expansions.at n=9A124640
- Measures of entanglement in 3-qbits.at n=19A129548
- Composite numbers n such that 8*n^2-2*n-1 divides the primitive part U(n) of Fibonacci(n).at n=28A159234
- Numbers k such that 2^k-61 is prime.at n=34A182156
- Numbers k such that there is 1 prime between 100*k and 100*k + 99.at n=5A186393
- Number of n-variations of the set {1,2,...,n+1} satisfying p(i)-i in {-2,0,2}, i=1..n (an n-variation of the set N_{n+s} = {1,2,...,n+s} is any 1-to-1 mapping p from the set N_n = {1,2,...,n} into N_{n+s} = {1,2,...,n+s}).at n=19A217694
- Numbers n whose square representation in base 10 can be split into three parts whose sum is n.at n=37A254648
- Squarefree numbers that are k*A005117(k) for some k.at n=43A257832
- a(n) = n*(n+1)*(n+2)*(n+3)*(2*n^2+6*n+7)/360.at n=10A259181
- Number of n X 3 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.at n=6A278671
- Number of nX7 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.at n=2A278675
- T(n,k)=Number of nXk 0..1 arrays with rows in nondecreasing lexicographic order and columns in nonincreasing lexicographic order, but with exactly one mistake.at n=38A278676