8039
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8040
- 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
- 8038
- Möbius Function
- -1
- Radical
- 8039
- 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
- 189
- 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
- 1011
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Where the prime race among 7k+1, ..., 7k+6 changes leader.at n=43A007354
- Powers of fourth root of 11 rounded down.at n=15A018075
- Powers of fourth root of 11 rounded to nearest integer.at n=15A018076
- Numbers k such that the continued fraction for sqrt(k) has period 80.at n=25A020419
- 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 89.at n=9A031587
- Fibonacci iteration starting with (1, a(n)) leads to a "nine digits anagram".at n=14A034587
- Primes p such that the Fibonacci iterations starting with (1, p) lead to a "nine digits anagram".at n=1A034588
- a(n) is the smallest prime p such that p^2 divides n^(p-1) - 1.at n=38A039951
- Numbers having four 1's in base 6.at n=32A043376
- Numbers having three 2's in base 9.at n=34A043463
- Primes with first digit 8.at n=20A045714
- T(n,n-3), array T as in A047100.at n=7A047105
- Primes for which only two iterations of 'Prime plus its digit sum equals a prime' are possible.at n=38A048524
- Least prime in A031932 (lesser of 14-twins) whose distance to the next 14-twin is 6*n.at n=15A052356
- Primes p such that p^8 reversed is also prime.at n=43A059701
- Primes with 11 as smallest positive primitive root.at n=33A061324
- A B_2 sequence: a(n) is the smallest prime such that the pairwise sums of distinct elements are all distinct.at n=42A062294
- Safe primes (A005385) (p and (p-1)/2 are primes) such that 12*p+1 is also prime.at n=26A075707
- Least k such that the class number of quadratic order of discriminant D=-4k equals p, where p runs through the primes.at n=29A079029
- Prime numbers using only the curved digits 0, 3, 6, 8 and 9.at n=30A079652