6659
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6660
- 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
- 6658
- Möbius Function
- -1
- Radical
- 6659
- 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
- 93
- 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
- 858
- 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=41A000353
- Molien series for alternating group Alt_8 (or A_8).at n=37A008631
- Numbers k such that the continued fraction for sqrt(k) has period 90.at n=8A020429
- Let q_k=p(p+2) be product of k-th pair of twin primes; sequence gives values of p such that (q_k)^2 > q_{k-i}q_{k+i} for all 1 <= i <= k-1.at n=41A021005
- 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 81.at n=8A031579
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 36 ones.at n=25A031804
- Number of partitions of n with equal number of parts congruent to each of 0 and 2 (mod 3).at n=42A035535
- Total number of prime parts in all partitions of n.at n=24A037032
- Discriminants of imaginary quadratic fields with class number 23 (negated).at n=20A046020
- a(n) is the smallest prime factor of 1 + lcm(1..k) where k is the n-th prime power A000961(n).at n=13A051454
- Fourth term of strong prime quintets: p(m-2)-p(m-3) > p(m-1)-p(m-2) > p(m)-p(m-1) > p(m+1)-p(m).at n=17A054811
- Denoting 5 consecutive primes by p, q, r, s and t, these are the values of q such that q, r and s have 10 as a primitive root, but p and t do not.at n=15A060261
- Primes of the form 666*k - 1.at n=3A063472
- Primes such that prime(p) +- pi(p) are simultaneously prime.at n=14A065117
- Define the composite field of a prime q to be f(q) = (t,s) if p, q, r are three consecutive primes and q-p = t and r-q = s. This is a sequence of primes q with field (6,2).at n=35A073651
- Primes p such that 3p is equidistant from consecutive prime twin pairs.at n=39A074931
- a(0) = 2, a(n)=smallest prime > a(n-1) such that a(n) - a(n-1) == 0 mod n!.at n=7A087524
- Numbers of the form prime(prime(n)+1), with n satisfying prime(n)+2 = prime(n+1).at n=33A088985
- Smallest member of a pair of consecutive twin prime pairs that have two primes between them.at n=20A089634
- Number of planar partitions of n with exactly 4 rows.at n=14A091358