15809
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15810
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15808
- Möbius Function
- -1
- Radical
- 15809
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 190
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1845
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numerators of continued fraction convergents to sqrt(245).at n=6A041458
- Numerators of continued fraction convergents to sqrt(500).at n=8A041954
- Numerators of continued fraction convergents to sqrt(980).at n=8A042896
- Last member of a sexy prime quadruple: value of p+18 such that p, p+6, p+12 and p+18 are all prime.at n=30A046124
- Fourth term of balanced prime quartets: p(m-2)-p(m-3) = p(m-1)-p(m-2) = p(m)-p(m-1).at n=10A054803
- Binomial transform of A073817: a(n)=Sum(Binomial(n,k)*A073817(k),(k=0,..,n)).at n=9A075116
- Primes of the form 128n+65.at n=31A105129
- Number of leaf nodes in a binary tree.at n=22A112088
- Father primes of order 8.at n=27A136077
- Prime numbers p such that p^3 - (p+1)^2 and p^3 + (p+1)^2 are both primes.at n=17A137476
- a(n) is n-th prime == -1 (mod 6n).at n=30A138905
- Primes of the form 210k + 59.at n=37A140852
- Primes congruent to 17 mod 47.at n=39A142368
- Primes congruent to 15 mod 53.at n=33A142545
- Primes congruent to 56 mod 59.at n=35A142783
- Primes congruent to 10 mod 61.at n=33A142808
- Number of ways to place zero or more nonadjacent 0,0 1,0 1,1 2,1 3,1 4,1 4,2 5,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155370
- Primes p such that p^2 - 2 is a 5-almost prime.at n=21A156620
- Lesser of two consecutive primes p,q such that q^2 - p^2 + 1 = the square of a prime.at n=45A157750
- Odd primes which can never divide 2^a+2^b+1.at n=26A179113