6971
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
- 6972
- 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
- 6970
- Möbius Function
- -1
- Radical
- 6971
- 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
- 57
- 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
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 896
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Smallest prime p==3 (mod 8) such that Q(sqrt(-p)) has class number 2n+1.at n=22A002148
- Primes of the form k^2 - k - 1.at n=41A002327
- Primes that remain prime through 3 iterations of function f(x) = 4x + 9.at n=21A023282
- a(n) = Sum_{k=1..n} k*[ (n/k)*[ n/k ] ].at n=42A024932
- 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=9A031581
- Primes that are concatenations of n with n + 2.at n=10A032625
- Numbers whose set of base-13 digits is {2,3}.at n=25A032813
- Primes with multiplicative persistence value 5.at n=15A046505
- Primes p from A031924 such that A052180(primepi(p)) = 19.at n=11A052235
- Primes of the form p^2 + p - 1 when p is prime.at n=10A053185
- Numbers k such that (20^k+1)/21 is a prime.at n=6A057186
- Primes p such that x^41 = 2 has no solution mod p.at n=22A059236
- Smallest number such that GCD of EulerPhi of 2 consecutive integer equals 2n.at n=40A063444
- (p^2-5)/4 for odd primes p.at n=37A074367
- Prime numbers occurring at integer Pythagorean distance (radius) from 1 in Ulam square prime-spiral. Primes on axes are excluded.at n=17A078765
- First row of square array A082011.at n=40A082012
- a(n) = 4*n^2 + 6*n + 1.at n=41A082108
- Coefficient of s(2n) in s(n,n) * s(n,n) * s(n,n) * s(n,n) * s(n,n), where s(2n) is the Schur function corresponding to the trivial representation, s(n,n) is a Schur function corresponding two the two row partition and * represents the inner or Kronecker product of symmetric functions.at n=10A082437
- a(n) = A085956(3n+1).at n=28A086362
- Number of square plane partitions of n.at n=30A089299