15315
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
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 24528
- Proper Divisor Sum (Aliquot Sum)
- 9213
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8160
- Möbius Function
- -1
- Radical
- 15315
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 84
- 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
- Pisot sequence T(2,9), a(n) = floor(a(n-1)^2/a(n-2)).at n=6A020728
- McKay-Thompson series of class 45b for Monster.at n=56A058686
- Smallest multiple of n beginning and ending in n and having a digit sum of n, or 0 if no such number exists.at n=14A077739
- Smallest multiple of n beginning and ending in n and with a digit sum that is divisible by n.at n=14A078213
- Number of (w,x,y) with all terms in {0,...,n} and |w-x| + |x-y| + |y-w| < w+x+y.at n=27A213488
- Numbers n such that n+(n+1), n^2+(n+1)^2, n+(n+1)^2, n^2+(n+1) are all prime.at n=22A216270
- Numbers which are the roots of distinct not-previously-encountered side-trees ("tendrils") sprouting from the side of the infinite beanstalk (see A213730).at n=27A218612
- Expansion of Product_{k>=1} 1/(1-x^(3*k-2))^(3*k-2).at n=29A262947
- Numbers k such that (82*10^k + 449)/9 is prime.at n=18A282809
- Numbers that are the sum of six fourth powers in four or more ways.at n=13A345561
- Numbers that are the sum of six fourth powers in exactly four ways.at n=13A345816
- a(0) = 1; a(n) = a(n-1) + a(floor(n/2)) + 1.at n=47A346912