12397
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 16416
- Proper Divisor Sum (Aliquot Sum)
- 4019
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9240
- Möbius Function
- 0
- Radical
- 1771
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 138
- Smith Number
- no
- 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
- a(n) = n*(n+1)*(n+2)*(n+7)/24.at n=21A005582
- a(n) = 49*(n-1)*(n-2)/2.at n=21A027469
- Odd numbers to the right of the central elements of the (2,1)-Pascal triangle A029653 that are different from 1.at n=40A029668
- Upper members of a "good pair" of the form (k, 2*k +- 1).at n=42A046862
- A049031/2.at n=28A049032
- Numbers k such that gcd(3k,8^k+1) = 3 but k does not divide the numerator of B(2k) (the Bernoulli numbers).at n=17A070193
- Numbers k such that (10^k-1)/9 + 4*10^floor(k/2) is a palindromic wing prime (a.k.a. near-repdigit palindromic prime).at n=8A077783
- Greatest number having exactly n representations as ab+ac+bc with 0 < a < b < c.at n=12A094377
- a(n) is the smallest integer m such that A039995(m)=n.at n=18A094535
- Row sums of the number triangle A098505.at n=16A098506
- a(n) = (Product_{i=1..n} i^i) / denominator( Sum_{j=1..n} j*(j+1)/2 / (Product_{k=0..j-1} j!/k!) ).at n=49A105658
- Number of nonempty subsets of {1,2,...,n} with no gap of length greater than 4 (a set S has a gap of length d if a and b are in S but no x with a < x < b is in S, where b-a=d).at n=13A119407
- 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=19A120939
- Least number k such that 4*(k*(2^p-1))^2 + 1 is prime where 2^p-1 is a Mersenne prime (p in A000043).at n=23A132192
- a(n) = binomial(n+1,2)*7^2.at n=22A162942
- Half the number of n X n binary arrays with no 1 having an adjacent 1 both above and to its left.at n=3A184754
- Half the number of n X 4 binary arrays with no 1 having an adjacent 1 both above and to its left.at n=3A184756
- T(n,k)=Half the number of nXk binary arrays with no 1 having an adjacent 1 both above and to its left.at n=24A184761
- G.f.: (1+x^3)/(1-x-x^6).at n=39A193941
- Number of pairs of parallel diagonals in a regular n-gon.at n=46A211379