5807
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
- 5808
- 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
- 5806
- Möbius Function
- -1
- Radical
- 5807
- 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
- 111
- 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
- 762
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p == 7, 19, 23 (mod 40) such that (p-1)/2 is also prime.at n=37A000353
- Wagstaff numbers: numbers k such that (2^k + 1)/3 is prime.at n=23A000978
- If a, b in sequence, so is ab+7.at n=40A009312
- a(n) = Sum_{k = 1..n} k*floor((n + prime(k))/k).at n=45A024929
- 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 75.at n=19A031573
- Primes of form x^2+59*y^2.at n=34A033238
- Number of n-node rooted identity trees of height at most 6.at n=16A038085
- Primes for which only two iterations of 'Prime plus its digit sum equals a prime' are possible.at n=31A048524
- Primes p such that pp'-2 is prime, where p' denotes the next prime after p.at n=34A048797
- Molien series for group G_{1,2}^{8} of order 1536.at n=23A051462
- Primes p such that p-6, p and p+6 are consecutive primes.at n=41A053070
- First differences of A001628 (Fibonacci convolution).at n=12A055243
- 5-morphic but not bimorphic, automorphic nor trimorphic.at n=32A056036
- Numbers k such that k^4 == 1 (mod 5^4).at n=37A056091
- Number of partitions of n with positive rank.at n=33A064173
- a(n) = 48*n^2 - 1.at n=11A065532
- Primes p such that (p-1)/2 and (p-3)/4 are also prime.at n=13A066179
- Numbers k such that 2^k + 1 has just two distinct prime factors.at n=43A066263
- Primes of the form sum 6d/(2 + mu(d)) for some k and all d dividing k.at n=16A069548
- Numbers k such that 2^k + 1 is the product of two distinct primes.at n=41A073936