6947
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
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 6948
- 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
- 6946
- Möbius Function
- -1
- Radical
- 6947
- 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
- 106
- 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
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 891
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers that are the sum of 8 positive 7th powers.at n=27A003375
- Primes that remain prime through 2 iterations of the function f(x) = 5x + 4.at n=43A023253
- Primes with property that when squared all even digits occur together and all odd digits occur together.at n=40A030480
- 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 83.at n=5A031581
- Start of a string of exactly 2 consecutive (but disjoint) pairs of twin primes.at n=18A035790
- Primes p such that x^23 = 2 has no solution mod p.at n=41A040984
- Primes of the form 4*k^2 + 4*k + 59.at n=36A048988
- Recip transform of 2*(1 + x^2 + x^4 + x^6)-1/(1-x).at n=13A049164
- a(n) = Sum_{i=0..n} T(i,n-i), array T as in A049723.at n=18A049724
- Numbers m such that m divides Sum_{k = 1..m} A000005(k).at n=14A050226
- First of four consecutive primes that comprise two sets of twin primes.at n=30A053778
- Primes p such that p^6 + p^3 + 1 is prime.at n=36A066100
- Lowest primes in twin packs.at n=24A069457
- Group the natural numbers such that the n-th group contains n terms and the group sum is the smallest possible prime: (2), (1, 4), (3, 5, 9), (6, 7, 8, 10), (11, 12, 13, 14, 17), (15, 16, 18, 19, 20, 21), ... Sequence gives group sums.at n=23A075345
- Near twin primes of order 12: twin primes p,p+2 such that p+12 and p+14 are primes.at n=30A079292
- a(n) = smallest prime > n*prime(n).at n=39A079779
- a(1)=2; a(n) for n>1 is the smallest prime number > a(n-1) such that the concatenation of all previous terms is also prime.at n=22A080155
- Primes that are the sum of 9 consecutive primes.at n=40A082251
- a(n) = A061419(n) - A002379(n).at n=23A083198
- Middle q of three consecutive primes p,q,r, such that one adjacent prime is near, the other is far and the ratio of the differences (whichever of (r-q)/(q-p) or (q-p)/(r-q) is greater than 1) sets a record.at n=9A084105