17839
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17840
- 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
- 17838
- Möbius Function
- -1
- Radical
- 17839
- 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
- 216
- 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
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 2046
- 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) = 10x + 3.at n=40A023300
- Primes that remain prime through 4 iterations of function f(x) = 10x + 3.at n=4A023328
- Primes of the form n^2 + (n+1)^2 + (n+2)^2 + (n+3)^2 + (n+4)^2 + (n+5)^2.at n=16A027867
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 78 ones.at n=15A031846
- Primes p such that p, p+12, p+24 are consecutive primes.at n=13A052188
- a(n) is the least prime p, such that next_prime(2*p) - 2*p = 2*n - 1.at n=25A059846
- Primes arising in A085042: a(n) = the n-th partial sum of A085042.at n=30A085043
- Numbers k such that 10^k + 7*R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=17A089147
- Primes p for which Sum_{1 <= n < p} (n!|p) == 0 (mod p), where (n!|p) is the Legendre symbol.at n=31A131652
- Primes of the form 55x^2+10xy+199y^2.at n=33A140632
- Primes congruent to 31 mod 53.at n=40A142561
- Primes congruent to 21 mod 59.at n=34A142748
- Primes congruent to 27 mod 61.at n=35A142825
- Lesser of two consecutive primes, p < q, such that both p*q+p-q and p*q-p+q are prime numbers.at n=25A154553
- First of a run of 4 or more consecutive primes which all equal 1 (mod 3).at n=37A185942
- Consider two consecutive primes {p,q} such that {P=2p-q,Q=2q-p} are both prime. Sequence gives lesser primes p.at n=38A186169
- a(n) = 3*a(n-1) + 4*a(n-2) + a(n-3) with a(0)=3, a(1)=3, a(2)=17.at n=7A215076
- Numbers of espalier polycubes of a given volume in dimension 4.at n=25A229917
- Primes p such that p - 2 and p^3 - 2 are also prime.at n=40A240126
- a(n) = prime(k+1) with k = n^2 + prime(n)^2.at n=13A243894