12091
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
- 4
- Divisor Sum
- 12312
- Proper Divisor Sum (Aliquot Sum)
- 221
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11872
- Möbius Function
- 1
- Radical
- 12091
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 94
- Smith Number
- yes
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/(2*n)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=40A024845
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 56 ones.at n=29A031824
- n-th 4k+1 prime times (n+1)st 4k+3 prime.at n=13A048628
- a(n) = prime(n)*prime(n+2).at n=27A090076
- Product of the n-th sexy prime pair.at n=18A111192
- a(n) = numerator of b(n), where b(1)=1, b(n) = Sum_{1<=k<n, gcd(k,n)=1} 1/b(k).at n=6A127941
- Numbers having exactly two distinct prime factors p, q with q = p+6.at n=34A143205
- Second bisection of A061039.at n=53A144450
- a(n) = prime(n) times the n-th nonnegative noncomposite.at n=29A176098
- Numbers n such that exactly two positive d in the range d <= n/2 exist which divide binomial(n-d-1, d-1) and which are not coprime to n.at n=28A178098
- Smallest k such that 36^k mod k = n.at n=41A178197
- a(n) = 8*n^2 - 2*n + 1.at n=39A185438
- a(n) = c({1}^n), the Cantor tuple function c applied to an n-tuple of 1's.at n=5A226588
- S_5 sequence in partition of integers > 1 described in A240521.at n=33A240522
- Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly three bit positions.at n=31A261075
- Sequence of pairwise relatively prime numbers of class P_5 (see comment in A275246).at n=14A275249
- Records in A249860.at n=40A276705
- G.f.: Sum_{n>=0} (n+1) * (x + x^n)^n.at n=78A325997
- a(n) = 4*p(n-1)*p(n+1) - p(n)^2, where p(k) = k-th prime.at n=16A327447
- Number of compositions of n into distinct parts such that the difference between any two parts is at least two.at n=38A327710