17387
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17388
- 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
- 17386
- Möbius Function
- -1
- Radical
- 17387
- 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
- 84
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1999
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes that remain prime through 3 iterations of function f(x) = 5x + 4.at n=25A023284
- Twin-prime-indexed primes (TWIPS): members of a pair of twin primes whose prime index is also a member of a pair of twin primes.at n=37A087373
- Numbers which are primes and which remain prime for three successive applications of incrementing each digit by 2 with carries ignored.at n=21A088787
- Numbers k such that numerator(Bernoulli(2*k)/(2*k)) is different from numerator(Bernoulli(2*k)/(2*k*(2*k-1))).at n=67A090495
- a(n) is the smallest lesser of twin prime p, such that prime(2 + p) - prime(p) = 2n (cf. A096474).at n=27A096475
- Primes of the form 6n^2 - 2n - 1.at n=19A099007
- Primes p such that 6p + 7 is a square.at n=41A110014
- Primes p such that p+2, p*(p+2)+18 and p*(p+2)+20 are also prime.at n=3A130737
- Primes congruent to 44 mod 47.at n=39A142395
- Primes congruent to 41 mod 59.at n=28A142768
- Primes congruent to 2 mod 61.at n=31A142800
- Number of lower triangles of a 3 X 3 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by two or less.at n=17A195249
- Primes p of the form p = prime(n) + prime(n+1) - 5 and p = prime(k) + prime(k+1) + 5.at n=33A207992
- Number of finite, negative, Archimedean, commutative, totally ordered monoids of size n (semi-groups with a neutral element that is also the top element).at n=9A253948
- Least positive integer k such that both k and k*n belong to the set {m>0: prime(prime(m))-prime(m)+1 = prime(p) for some prime p}.at n=51A260753
- n such that A275391(n) = n-2.at n=54A275800
- Number of n X 4 0..1 arrays with every element unequal to 0, 1, 2, 4 or 8 king-move adjacent elements, with upper left element zero.at n=8A305241
- Lesser of the pairs of twin primes in A001122.at n=41A319248
- Primes p such that p+2 is prime and p+A001414(p+1)+(p+2) is prime.at n=36A330488
- The number of twin binary Niven numbers (k, k+1) such that k <= 2^n.at n=20A337079