11827
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 11828
- 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
- 11826
- Möbius Function
- -1
- Radical
- 11827
- 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
- 81
- 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
- 1418
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Catafusenes (see reference for precise definition).at n=8A044049
- Discriminants of imaginary quadratic fields with class number 13 (negated).at n=30A046010
- Second member of a sexy prime quadruple: value of p+6 such that p, p+6, p+12 and p+18 are all prime.at n=24A046122
- Primes at which the difference pattern X42Y (X and Y >= 6) occurs in A001223.at n=26A052164
- Third term of strong prime 5-tuples: p(m-1)-p(m-2) > p(m)-p(m-1) > p(m+1)-p(m) > p(m+2)-p(m+1).at n=30A054810
- Primes of the form 4*k^2 + 163.at n=46A057604
- a(1) = 1, a(n+1) is the sum of a(n) and ceiling( arithmetic mean of a(1) ... a(n) ).at n=34A065095
- First differences give A052849.at n=7A066237
- Primes which can be expressed as concatenation of cubes.at n=29A066592
- Primes p such that p-1 divides 2^p-2.at n=16A069051
- Primes on axis of Ulam square spiral (with rows ... / 7 8 9 / 6 1 2 / 5 4 3 / ... ) with origin at (1).at n=47A078784
- Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[4,2,6]; short d-string notation of pattern = [426].at n=8A078850
- a(n+1) is smallest number with a(n+1)^n > (a(n)+1)^(n+1), with a(1)=1.at n=9A080870
- a(n) is the number of nonnegative integers k less than 10^n such that the decimal representation of k lacks the digits 1,2,3, at least one of digits 4,5 and at least one of digits 6,7,8,9.at n=4A126635
- Prime chain of 128 terms, including 104 distinct primes, consisting of the output of eight equations that alternate sequentially within a procedural expression of a single polynomial. The equations are either subsequences of x^2 - 79x + 1601 or transforms with one exception: 100x^2 - 2260x + 12959. The other four distinct equations are Euler-derived: 25x^2 - 1185x + 14083, 25x^2 - 775x + 6047, 100x^2 - 2280x + 13159, 100x^2 - 4160x + 43427.at n=9A140708
- Primes of the form 210k + 67.at n=29A140855
- Primes congruent to 24 mod 37.at n=39A142133
- Primes congruent to 19 mod 41.at n=35A142216
- Primes congruent to 2 mod 43.at n=35A142251
- Primes congruent to 30 mod 47.at n=27A142381