13018
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 20448
- Proper Divisor Sum (Aliquot Sum)
- 7430
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6204
- Möbius Function
- -1
- Radical
- 13018
- 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
- 76
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = Sum_{i=0..n} Sum_{j=0..n} T(i,j), T given by A026725.at n=12A026734
- Minimum sum of n distinct positive numbers, any n-1 of which sum to a square.at n=10A035305
- Numbers k such that 273*2^k-1 is prime.at n=39A050895
- Number of partitions of n having exactly 1 part that appears exactly once.at n=44A116596
- Expansion of eta(q^3) * eta(q^33) / ( eta(q)* eta(q^11)) in powers of q.at n=44A128663
- Partial sums of A006156.at n=21A177736
- Number of fixed poly-[3^3.4^2]-tiles (polyhouses) (holes allowed) with n cells.at n=7A197158
- Numbers n such that Bernoulli number B_{n} has denominator 282.at n=35A272184
- a(n) = Sum_{k=1..n} prime(k)^2*floor(n/prime(k)) .at n=47A280385