15455
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20304
- Proper Divisor Sum (Aliquot Sum)
- 4849
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11200
- Möbius Function
- -1
- Radical
- 15455
- 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
- 89
- 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
- Factorable subsets: the number of proper subsets S of {1,2,...,n} that can be expressed in the form S=A*B, where S is defined to be the set {a(i)*b(j)| a(i) in A, b(j) in B}.at n=26A068594
- Derived from central terms (A127090) of triangle A127082; a(n) = A127090(n)/(n+1).at n=5A127091
- Partial sums of A003325.at n=40A139211
- Maximal term of TRIP-Stern sequence of level n corresponding to permutation triple (e,23,e).at n=28A271488
- Number of terms in the fully expanded n-th derivative of x^(x^x).at n=28A281434
- Numbers k such that 395*2^k+1 is prime.at n=9A323042
- a(n) = (8*n^3 + 15*n^2 + 13*n)/6.at n=22A332698
- Number of distinct, irreducible ways that a Pythagorean hyperrectangle of 2 or more dimensions can produce diagonal length n.at n=46A375338
- Number of abelian/medial racks of order n, up to isomorphism.at n=8A383144