12627
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 19344
- Proper Divisor Sum (Aliquot Sum)
- 6717
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7920
- Möbius Function
- 0
- Radical
- 4209
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 156
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- Least k such that 1+2+...+k >= E{1,2,...,n}, where E is the 4th elementary symmetric function.at n=17A027918
- Number of partitions of n into parts not of the form 21k, 21k+2 or 21k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 9 are greater than 1.at n=40A035980
- Numbers n such that 73*2^n-1 is prime.at n=9A050562
- Number of 3-rowed binary matrices with n ones and no zero columns, up to row and column permutation.at n=27A058053
- a(n) = 4*a(n-1) + 3*a(n-2), a(0)=1, a(1)=6.at n=6A109115
- a(1)=1. a(n) = a(n-1) + (largest integer occurring among {a(1),a(2),a(3),...,a(n-1)} that is coprime to n).at n=20A120939
- 1/4 the number of n X n 0..3 symmetric matrices with every element equal to zero or two horizontal and vertical neighbors.at n=3A211079
- Number of (w,x,y) with all terms in {0,...,n} and |w-x|+|x-y|+|y-w| > w+x+y.at n=35A213486
- Difference between 10^n and the first prime of gap 6 > 10^n.at n=48A227435
- Number of 3-element subsets of {1,...,n} whose sum has more than 2 divisors.at n=46A241563
- Indices of primes in the 10th-order Fibonacci number sequence, A127194.at n=29A257073
- a(n) = 99*2^n - 45 (n>=0).at n=7A304172
- a(n) is the integer part of the area of a regular n-gon whose side lengths are n.at n=17A374296
- Zero-avoiding Fibonacci sequence: a(n) is the largest zeroless number that can be written as a(i) + a(j) where 1 <= i < j < n with a(1) = a(2) = 1.at n=21A374924
- Number of nonisomorphic semigroups with n elements satisfying the equation xyz = xz.at n=20A390162