11549
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 11550
- 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
- 11548
- Möbius Function
- -1
- Radical
- 11549
- 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
- 130
- 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
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- yes
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1391
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p such that 1 + product of primes up to p is prime.at n=13A005234
- Supersingular primes of the elliptic curve X_0 (11).at n=17A006962
- Coordination sequence for MgZn2, Mg position.at n=27A009939
- Primes that remain prime through 3 iterations of the function f(x) = 2*x + 1.at n=12A023272
- Convolution of natural numbers with Beatty sequence for tau^2 A001950.at n=28A023542
- Super-4 Numbers (4 * n^4 contains substring '4444' in its decimal expansion).at n=8A032744
- Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 15.at n=14A050964
- Primes p such that p^9 reversed is also prime.at n=35A059702
- Primes starting a Cunningham chain of the first kind of length 4.at n=7A059763
- Smaller of twin primes whose middle term is a multiple of A002110(4)=210.at n=14A060230
- Smaller of twin primes whose middle term is a multiple of A002110(5)=2310.at n=2A060231
- Positive numbers whose product of digits is 9 times their sum.at n=31A062041
- Numbers n such that n, 2n+1, 3n+2, 4n+3 are primes.at n=5A067257
- Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=19A075585
- Primes p such that 11 is the largest of all prime factors of the numbers between p and the next prime (cf. A052248).at n=17A080187
- a(1) = 7 then the smallest number such that the forward as well as the reverse n-th partial concatenation is a prime for n>1. (Reverse concatenation is taken term-wise and not digit-wise).at n=38A083994
- Table read by rows where i-th row consists of primes P of the form P=j*P(i)# -1 or P=j*P(i)# +1 with 0 < j < P(i+1). Here P(r)# = A002110.at n=35A087715
- Smaller of twin primes of the form P=j*P(i)#-1 and P=j*P(i)#+1 with 0 < j < P(i+1), where P(i) denotes i-th prime and P(i)# the i-th primorial number A002110(i).at n=12A087732
- a(n) = (n^3 + 24*n^2 + 65*n + 36)/6.at n=34A087863
- Choose a(n) so that 2*3*5*13*...*a(n) - 1 is prime; a(n) is prime; and a(n) > a(n-1).at n=45A087898