15549
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 21312
- Proper Divisor Sum (Aliquot Sum)
- 5763
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10080
- Möbius Function
- -1
- Radical
- 15549
- 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
- 53
- 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 unrooted achiral trees with n nodes.at n=36A003244
- Crystal ball sequence for diamond.at n=26A007904
- Numbers that are the product of 3 prime factors whose concatenation is a palindrome.at n=34A046452
- a(n) = Sum_{k=0..floor(n/2)} binomial(n,2*k)*Fibonacci(k+1).at n=13A101891
- The PolyLog functional part of A008292 (the Eulerian numbers) is treated as a curvature to give a set of polynomial triangle sequence coefficients: p(x,n)=Sum[A008292(n,m)*x^(m-1),{m,0,n}]; q(x,n)=k from Solve[FullSimplify[ExpandAll[p[x, n]/(x - 1)^n]] - (1 + k/x^2) == 0, k].at n=39A146540
- a(n) = 676*n + 1.at n=22A158386
- a(0)=0, then a(n) = smallest odd k > a(n-1) such that 6*k^prime(n)-1 is prime.at n=40A283676
- Denominator of (1/3)*n*(n + 2)/((1 + 2*n)*(3 + 2*n)).at n=35A300295