12109
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12110
- 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
- 12108
- Möbius Function
- -1
- Radical
- 12109
- 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
- 68
- 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
- 1450
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of n-step spiral self-avoiding walks on hexagonal lattice, where at each step one may continue in same direction or make turn of 2*Pi/3 counterclockwise.at n=33A000511
- a(n) = A259095(2n,n).at n=21A005575
- Coordination sequence for MgNi2, Position Mg1.at n=27A009936
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 73.at n=0A031661
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 68 ones.at n=12A031836
- Euclid-Mullin sequence (A000945) with initial value a(1)=131071 instead of a(1)=2.at n=22A051331
- Second term of weak prime quintets: p(m)-p(m-1) < p(m+1)-p(m) < p(m+2)-p(m+1) < p(m+3)-p(m+2).at n=26A054824
- Number of mobiles (circular rooted trees) with n nodes and 3 leaves.at n=25A055341
- Primes in which neighboring digits differ at most by 1.at n=47A068148
- Prime(p)-4 for primes p such that prime(p) - 4 is prime.at n=32A094069
- Largest of five consecutive primes the sum of the digits of each of which is prime.at n=29A106717
- Largest of six consecutive primes the sum of the digits of each of which is prime.at n=11A106720
- Largest prime of the set of four consecutive primes whose sum of digits is a set of four distinct primes.at n=27A106818
- Numbers k such that 66 * 10^k + 1 is prime.at n=10A109503
- Prime Friedman numbers.at n=5A112419
- Primes of the form 7x^3+x+1.at n=5A114353
- Primes of the form k^2 + 9.at n=15A138353
- Primes congruent to 10 mod 37.at n=40A142119
- Primes congruent to 14 mod 41.at n=38A142211
- Primes congruent to 26 mod 43.at n=30A142275