12127
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
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12376
- Proper Divisor Sum (Aliquot Sum)
- 249
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11880
- Möbius Function
- 1
- Radical
- 12127
- 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
- 143
- Smith Number
- no
- 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
- Number of triples (i,j,k) with 1 <= i < j < k <= n and gcd(i,j,k) = 1.at n=44A015616
- Numerators of continued fraction convergents to sqrt(308).at n=6A041580
- Indices of primes in sequence defined by A(0) = 71, A(n) = 10*A(n-1) + 41 for n > 0.at n=20A101143
- a(1) = 4; a(n) is smallest semiprime > 2*a(n-1).at n=11A117880
- This sequence and A139143 are complements. a(1) = 1, A139143(1) = 2, a(n+1) = a(n) + Sum_{k = 1..n} A139143(k).at n=38A139142
- Number of planar n X n X n binary triangular grids symmetric both under 120 degree rotation and reflection with no more than 8 ones in any 4 X 4 X 4 subtriangle.at n=11A153961
- Magic constants of 5 X 5 magic squares which consist of consecutive primes.at n=42A176571
- Number of perfect powers (A001597) < 2^n.at n=27A188951
- Numbers n such that phi(n) = phi(n+12) and n is not divisible by 2.at n=24A217141
- Numbers k that divide 2^k + 10.at n=8A245594
- Number of triples 0 <= i, j, k < n such that bitwise AND of i, j, k is 0.at n=26A269589
- Number of 2 X 2 matrices with all terms in {-n,..,0,..,n} and (sum of terms) = determinant.at n=17A281194
- Expansion of Sum_{p prime, i>=1} x^(p^i)/(1 - x^(p^i)) / Product_{p prime, j>=1} (1 - x^(p^j)).at n=37A281616
- Solution of the complementary equation a(n) = 2*a(n-1) - a(n-2) + b(n-1) + 3, where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=36A294871
- a(n) is a n-digit number; for k = 1..n, its k-th digit is the most frequent k-th digit among n-digit prime numbers; in case of a tie, preference is given to the least digit.at n=4A377571