12917
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12918
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12916
- Möbius Function
- -1
- Radical
- 12917
- 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
- 76
- 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
- 1538
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the continued fraction for sqrt(k) has period 65.at n=12A020404
- [ exp(16/17)*n! ].at n=6A030884
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 21.at n=17A051962
- Primes at which the difference pattern X24Y (X and Y >= 6) occurs in A001223.at n=28A052163
- Lesser of twin primes whose average is 6 times a prime.at n=32A060213
- Primes with 2 representations: p*q*r - 1 = u*v*w + 1 where p, q, r, u, v and w are primes.at n=35A063644
- First of three consecutive Ulam numbers (A002858) in arithmetic progression with difference 22.at n=6A068856
- Continued exponent expansion of the power series 1/(1-x); odd terms being numerators and even terms being denominators of the rational terms of the expansion: 1/(1-x) = e^[(a(1)/a(2))*x*e^[(a(3)/a(4))*x*e^[(a(5)/a(6))*x*e^[...]]]].at n=8A071787
- Primes p such that both p-1 and p+1 have at most 3 prime factors, counted with multiplicity; i.e., primes p such that bigomega(p-1) <= 3 and bigomega(p+1) <= 3, where bigomega(n) = A001222(n).at n=41A079153
- Number of divisors associated with the cyclic cases within the n-th group of least prime signatures.at n=14A079274
- Class 6- primes (for definition see A005109).at n=35A081425
- Primes which remain prime after one and after two applications of the rotate-and-add operation of A086002.at n=5A086003
- Primes which remain prime after one and after two and after three applications of the rotate-and-add operation of A086002.at n=0A086004
- Numbers m such that for increasing b the numbers of zeros in base b representation of m are monotonically decreasing, 1<b<m.at n=46A089969
- Primes such that the sum of the predecessor and successor primes is divisible by 41.at n=33A113157
- a(n) is largest prime < 6*a(n-1) for n > 1 with a(1) = 2.at n=5A126034
- Primes congruent to 2 mod 41.at n=39A142199
- Primes congruent to 17 mod 43.at n=40A142266
- Primes congruent to 39 mod 47.at n=32A142390
- Primes congruent to 30 mod 49.at n=37A142439