9839
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9840
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9838
- Möbius Function
- -1
- Radical
- 9839
- 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
- 47
- 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
- yes
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1214
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 99.at n=2A031597
- Primes of the form n*phi(n)-1 where phi is the Euler function (in order of appearance).at n=46A046078
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n-1 <= 2^(p+1), with a(1) = a(2) = 1 and a(3) = 2.at n=13A049939
- Primes p such that there is no Carmichael number pqr, p<q<r q, r primes.at n=9A051663
- a(n) = smallest number > a(n-1) such that a(1)*a(2)*...*a(n) + 1 and a(1)*a(2)*...*a(n) - 1 are primes.at n=28A051956
- Numbers which, when expressed as a sum of distinct primes with maximum product, use a non-maximal number of primes.at n=39A053020
- Numbers n such that 1n1, 3n3, 7n7 and 9n9 are all primes.at n=25A059677
- Primes p such that 1p1, 3p3, 7p7 and 9p9 are all primes.at n=6A059694
- Primes starting and ending with 9.at n=25A062335
- Primes p such that (p-1)/2 and (p-3)/4 are also prime.at n=20A066179
- Triangle of numbers relating two sequences (A073157 and A073155).at n=30A073154
- Safe primes (A005385) (p and (p-1)/2 are primes) such that 8*p+1 (A023228) is also prime.at n=30A075706
- Class 6- primes (for definition see A005109).at n=22A081425
- Primes whose 10's complement is a palindrome.at n=45A083017
- Primes that are a concatenation of a prime and its first digit.at n=28A085414
- Primes of the form 16*k-1 such that 4*k-1 and 8*k-1 are also primes.at n=10A101793
- a(n) = 6*n*(n-1) - 1.at n=41A103115
- Primes with digit sum = 29.at n=27A106766
- Primes such that the sum of the predecessor and successor primes is divisible by 37.at n=30A113156
- Prime quartet leaders: largest number of a prime quartet.at n=27A119892