6719
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6720
- 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
- 6718
- Möbius Function
- -1
- Radical
- 6719
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 137
- 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
- 867
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Hit polynomials.at n=7A001888
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite VNI = VPI-9 Rb44K4[Zn24Si96O240].48H2O starting with a T2 atom.at n=12A019253
- Numbers k such that the continued fraction for sqrt(k) has period 68.at n=20A020407
- Numbers whose least quadratic nonresidue (A020649) is 11.at n=41A025024
- Primes of form k^2 - 5.at n=21A028877
- 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=13A031579
- Lower prime of a pair of consecutive primes having a difference of 14.at n=34A031932
- Numerators of continued fraction convergents to sqrt(746).at n=5A042436
- Primes with multiplicative persistence value 5.at n=10A046505
- Revert transform of 2*x*(1 - x + x^4 - x^5 + x^6)-x/(1+x).at n=8A049188
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 3 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2.at n=13A049936
- Fourth term of weak 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=17A054826
- Primes such that replacing each digit d with d copies of the digit d produces a prime. Zeros are not allowed.at n=41A057628
- Primes with 11 as smallest positive primitive root.at n=32A061324
- The least number k = a(n) > a(n-1) for which k!/(k+1)^m for increasing m's.at n=39A061769
- Primes > 100 in which every substring of length 2 is also prime.at n=40A069488
- Least m which can be written as i*j+i+j in n different ways: A072670(m)=n.at n=27A072671
- Concatenation of n-th prime and n in decimal notation.at n=18A075110
- Sums of groups in A075635.at n=21A075636
- Safe primes (A005385) (p and (p-1)/2 are primes) such that 12*p+1 is also prime.at n=23A075707