16240
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 40
- Divisor Sum
- 44640
- Proper Divisor Sum (Aliquot Sum)
- 28400
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5376
- Möbius Function
- 0
- Radical
- 2030
- Omega Function (Ω)
- 7
- Little Omega Function (ω)
- 4
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
- 40
- 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
- yes
- Odd
- no
Appears in sequences
- Representation degeneracies for Ramond strings.at n=17A005305
- A triangle of numbers related to triangle A030524.at n=16A049352
- a(n) = a(n-1)^2 - a(n-2)^2 with a(0) = 0, a(1) = 2.at n=5A062000
- Numbers n such that the Diophantine equation x^4+y^5=n^4 has solutions.at n=28A070756
- Numbers k such that the number of steps to reach 1 in '3x+1' problem equals tau(k), the number of divisors of k.at n=23A070980
- Least area/6 of primitive Pythagorean triangles with even leg 4n.at n=47A096898
- Integers that are Rhonda numbers to more than one base.at n=32A100988
- Least n-bit number whose binary representation's substrings represent the maximal number (A112509(n)) of distinct integers.at n=13A112510
- a(1)=4, a(2)=6; for n > 2, a(n) = 2*a(n-1) + a(n-2) - 4*((n-1) mod 2).at n=10A162485
- Consider the base-3 Kaprekar map n->K(n) defined in A164993. Sequence gives numbers belonging to cycles, including fixed points.at n=13A164998
- Consider the base-3 Kaprekar map n->K(n) defined in A164993. Sequence gives numbers belonging to cycles of length greater than 1.at n=9A165000
- Molecular topological index of the Andrásfai graphs.at n=9A192790
- Triangle T(n,k), read by rows, given by (1,2,2,3,3,4,4,5,5,6,6,...) DELTA (1,0,1,0,1,0,1,0,1,0,1,0,1,...) where DELTA is the operator defined in A084938.at n=41A200659
- a(n) = 2*n*(n+1)*(n+2)/3.at n=28A210440
- Number of (w,x,y,z) with all terms in {1,...,n} and w*x+y*z>=n^2.at n=20A212132
- Antidiagonal sums of the convolution array A213849.at n=27A213850
- Number of compositions of n where the difference between largest and smallest parts equals 2 and adjacent parts are unequal.at n=25A214271
- Let h(m) denote the sequence whose n-th term is Sum__{k=0..n} (k+1)^m*T(n,k)^2, where T(n,k) is the Catalan triangle A039598. This is h(5).at n=3A228331
- a(n) = 2^(n+1) - (n-1)^2.at n=13A243860
- 9-step Fibonacci sequence starting with 0,0,0,0,0,0,0,1,0.at n=23A251746