12851
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13104
- Proper Divisor Sum (Aliquot Sum)
- 253
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12600
- Möbius Function
- 1
- Radical
- 12851
- 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
- 125
- 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
- Strong pseudoprimes to base 46.at n=20A020272
- Numbers whose set of base-16 digits is {2,3}.at n=25A032816
- Numbers k such that A055079(k) = 2^k.at n=31A057838
- Reverse of smallest prime factor of k = largest prime factor of k+1; a(1)=1.at n=14A071392
- Convolution of odd primes with themselves.at n=18A084370
- Nonprime numbers n such that phi(n) divides n^2 - 1, where phi(n) (A000010) is Euler's totient function.at n=16A098271
- Number of isomers of polyhex hydrocarbons with C_(2v) symmetry with nineteen hexagons.at n=14A120448
- a(n) = (2*n + 1)*(5*n + 6).at n=35A153127
- Integers of the form 4n+3 for which Sum_{i=1..u} J(i,4n+3) obtains value zero exactly 7 times, when u ranges from 1 to (4n+3). Here J(i,k) is the Jacobi symbol.at n=17A166057
- Odd nonprimes n such that n+d+1 is prime for all divisors d of n.at n=28A187554
- a(n) = 5^(4n+2) - 5^(3n+2) + 3 * 5^(2n+1) - 5^(n+1) + 1: the left Aurifeuillian factor of 5^(10n+5) - 1.at n=1A220979
- Numbers k whose decimal expansion can be split into at least two parts whose binary equivalents can be concatenated (in the same order) to form the binary expansion of the original number k.at n=31A237041
- Number of (5+2) X (n+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=25A252724
- Numbers whose multiset multisystem (A302242) is crossing.at n=32A324170
- Numbers that are the sum of seven fourth powers in five or more ways.at n=23A345571
- Numbers that are the sum of seven fourth powers in exactly five ways.at n=22A345827
- Triangle read by rows: T(n,k) = number of free polyominoes with n cells, where the maximum number of collinear cell centers on any line in the plane is k.at n=71A377942