13511
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13800
- Proper Divisor Sum (Aliquot Sum)
- 289
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13224
- Möbius Function
- 1
- Radical
- 13511
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 76
- 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
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 13 ones.at n=24A031781
- Term at which first number of height n occurs in Recamán's sequence A005132.at n=19A064292
- Number of permutations of length n that avoid the patterns 132, 4321.at n=21A116701
- a(n) = 3*a(n-1) - 2*a(n-2) - a(n-3) + a(n-4) with n>3, a(0)=1, a(1)=2, a(2)=3, a(3)=6.at n=18A131269
- Numbers k such that 9^k - 8 is prime.at n=16A177093
- Number of 0..4 arrays x(0..n-1) of n elements with each no smaller than the sum of its two previous neighbors modulo 5.at n=7A207096
- E.g.f.: Product_{n>=1} 1/(1 - x^n)^(1/n!).at n=7A209902
- Nonprimes such that it takes exactly 4 iterations of reverse-and-add digits to generate a prime.at n=35A245209
- Number of nX3 0..1 arrays with every element equal to 0, 2 or 3 horizontally or vertically adjacent elements, with upper left element zero.at n=12A301603
- Sequence shifts left when Weigh transform is applied four times with a(n) = n for n<2.at n=10A316104
- Number of integer partitions of n whose negated run-lengths are unimodal.at n=38A332638
- a(n) = A333552(A333551(n)): indices of terms in Recamán's sequence A005132 where the construction avoided a record-sized collision.at n=36A333553