15027
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20040
- Proper Divisor Sum (Aliquot Sum)
- 5013
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10016
- Möbius Function
- 1
- Radical
- 15027
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 89
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- Expansion of (1-x-sqrt(1-2*x-3*x^2-4*x^3))/(2*x*(1+x)).at n=12A071359
- Triangle read by rows of numbers of paths in a lattice satisfying certain conditions.at n=41A071950
- Smallest number m such that the concatenation of n+1 numbers m^0, m^1,..., m^(n-1), m^n is a prime.at n=42A096469
- a(n) = 52*n^2 - 1.at n=16A158640
- Number of 5-element nondividing subsets of {1, 2, ..., n}.at n=24A187492
- Riordan matrix (g(x),x*g(x)), where g(x) = (1-x-sqrt(1-2*x-3*x^2-4*x^3))/(2*x^2*(1+x)).at n=66A190252
- Number of length n+5 0..6 arrays with every six consecutive terms having five times some element equal to the sum of the remaining five.at n=1A249495
- T(n,k)=Number of length n+5 0..k arrays with every six consecutive terms having five times some element equal to the sum of the remaining five.at n=22A249497
- Number of length 2+5 0..n arrays with every six consecutive terms having five times some element equal to the sum of the remaining five.at n=5A249499
- Triangle read by rows: T(m,n) is the label of the largest square that an (m,n)-leaper (a generalization of a chess knight) reaches before it can no longer move, starting on a board with squares spirally numbered, starting at 1; 1 <= n < m. Each move is to the lowest-numbered unvisited square.at n=9A306197
- a(n) = Sum_{k=1..n} (k/gcd(n, k))^2.at n=43A332654