12889
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12890
- 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
- 12888
- Möbius Function
- -1
- Radical
- 12889
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1533
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes of the form m^2 + 3m + 9, where m can be positive or negative.at n=34A005471
- Coordination sequence for MgNi2, Position Mg2.at n=28A009935
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 80 ones.at n=6A031848
- Primes whose sum of digits is the perfect number 28.at n=30A048517
- Primes p such that p and p^2 have same digit sum.at n=21A058370
- Three-quadrant Ferrers graphs that partition n.at n=15A059776
- a(n) = 2*p + 2*n - 1, where p is the least prime such that next_prime(2*p) - 2*p = 2*n - 1.at n=17A059847
- Primes that are each the sum of two, three, and four consecutive composite numbers.at n=17A060339
- Primes with 13 as smallest positive primitive root.at n=34A061326
- a(1) = 2; k(1) = 0; for n > 1: k(n) = smallest number j >= k(n-1) such that 2*a(n-1) + j is prime; a(n) = 2*a(n-1) + k(n).at n=12A105120
- Indices of records in A109631.at n=30A109640
- Numbers k such that (3^k + 5^k)/8 = A074606(k)/8 is a prime.at n=10A122853
- a(n) = 104*n + 9977.at n=28A126978
- Primes of the form x^2 + 840*y^2.at n=32A139665
- Primes of the form 2*3*5*7*n+79.at n=29A141563
- Primes congruent to 15 mod 41.at n=30A142212
- Primes congruent to 32 mod 43.at n=31A142281
- Primes congruent to 11 mod 47.at n=31A142362
- Primes congruent to 2 mod 49.at n=41A142415
- Primes congruent to 10 mod 53.at n=28A142540