13500
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 48
- Divisor Sum
- 43680
- Proper Divisor Sum (Aliquot Sum)
- 30180
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3600
- Möbius Function
- 0
- Radical
- 30
- Omega Function (Ω)
- 8
- 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
- 138
- 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
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- yes
- Carmichael Number
- no
Classification
- Even
- yes
- Odd
- no
Appears in sequences
- Theta series of E_6 lattice.at n=14A004007
- Theta series of {E_6}* lattice.at n=42A005129
- Triangle whose (n,k)-th entry is 15^(n-k)*binomial(n,k).at n=11A027467
- a(n) = (n-1) * 15^(n-2).at n=3A027475
- 4th power of the lower triangular normalized partition matrix.at n=14A027518
- First diagonal of A027518.at n=4A027525
- a(n) = 4*n^3.at n=15A033430
- Sum of digits of numbers between 0 and (10^n)-1.at n=3A034967
- a(n) = ceiling((n^3)/2).at n=30A036486
- a(n) = floor((n^3)/2).at n=30A036487
- Unitary superperfect numbers: numbers n such that usigma(usigma(n)) = 2*n, where usigma(n) is the sum of unitary divisors of n (A034448).at n=8A038843
- Octahedral torus number: a(n) = n^2 + 2*(Sum_{k=1..n-1} k^2) - 2*(floor((n+1)/2)^2 + 2*(Sum_{k=1..floor((n+1)/2)-1} k^2)) + (1 - (-1)^n)/2.at n=29A050442
- a(n) = phi(2^n - 1)/2.at n=13A056742
- Triangle read by rows: T(n,k) is the number of labeled commutative monoids of order n with k idempotents and a fixed identity.at n=17A058160
- Numbers k such that sigma(k)+1 is a square and sets a new record for such squares.at n=34A063729
- a(n) = 15*n^2.at n=30A064761
- Numbers k having a partition k=Sum x_i for which Product k/x_i is also a way of factoring k.at n=45A068349
- Number of quinternary cubefree words of length n.at n=6A068539
- Largest proper divisor of n^3.at n=28A071378
- Row sums of triangle A074135.at n=29A074132