11491
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 11492
- 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
- 11490
- Möbius Function
- -1
- Radical
- 11491
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 37
- 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
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1386
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Least term in period of continued fraction for sqrt(n) is 5.at n=38A031429
- Primes of the form 30*p + 1 where p is also prime.at n=30A051646
- Difference between 2^n and the next larger or equal power of 3.at n=13A063004
- Smallest prime that is obtained by placing digits on both sides of the n-th prime. Or smallest prime that encompasses the n-th prime.at n=34A075595
- Expansion of g.f. -2*x/(1 - 5*x - sqrt(1-4*x) + x*sqrt(1-4*x) + 2*x^2).at n=9A078483
- Primes arising in A090266.at n=34A090267
- Smallest prime obtained by sandwiching prime(n) between identical digits, except that a(5) = 0.at n=34A090268
- Primes p of Erdos-Selfridge class 3+ with largest prime factor of p+1 not of class 2+.at n=39A129471
- The smallest prime p that makes the pair p+/-6n both primes while no other pair of p+/-6k+6*n, 0<k<n both primes.at n=39A139602
- Primes congruent to 21 mod 37.at n=33A142130
- Primes congruent to 11 mod 41.at n=34A142208
- Primes congruent to 10 mod 43.at n=29A142259
- Primes congruent to 23 mod 47.at n=28A142374
- Primes congruent to 25 mod 49.at n=29A142435
- Primes congruent to 16 mod 51.at n=41A142486
- Primes congruent to 43 mod 53.at n=28A142573
- Primes congruent to 51 mod 55.at n=32A142637
- Primes congruent to 34 mod 57.at n=34A142686
- Primes congruent to 45 mod 59.at n=24A142772
- Primes congruent to 23 mod 61.at n=23A142821