1091
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 1092
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1090
- Möbius Function
- -1
- Radical
- 1091
- 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
- 44
- 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
- 182
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of n-bead necklaces with beads of 2 colors and primitive period n, when turning over is not allowed but the two colors can be interchanged.at n=15A000048
- a(n) is the solution to the postage stamp problem with n denominations and 3 stamps.at n=22A001213
- Lesser of twin primes.at n=39A001359
- Number of partitions of n into parts 2, 3, 4, 5, 6, 7.at n=45A001996
- a(n) = least value of m for which Liouville's function A002819(m) = -n.at n=33A002053
- Smallest prime p==3 (mod 8) such that Q(sqrt(-p)) has class number 2n+1.at n=8A002148
- Number of partitions of n into parts 5k+2 or 5k+3.at n=55A003106
- Primes p with a Fibonacci primitive root g, i.e., such that g^2 = g + 1 (mod p).at n=49A003147
- Numbers that are the sum of 6 positive 5th powers.at n=27A003351
- Values of m in the discriminant D = -4*m leading to a new maximum of the L-function of the Dirichlet series L(1) = Sum_{k=1..oo} Kronecker(D,k)/k.at n=13A003420
- Divisible only by primes congruent to 6 mod 7.at n=34A004624
- Emirps (primes whose reversal is a different prime).at n=42A006567
- Primes of form x^3 + y^3 + z^3 where x,y,z > 0.at n=32A007490
- Smallest prime > n^2.at n=32A007491
- Primes == 3 (mod 8).at n=46A007520
- Prime triples: p; p+2 or p+4; p+6 all prime.at n=31A007529
- Molien series for 6-dimensional complex reflection group 4.U_4 (3) of order 2^9 .3^7 .5.7.at n=30A008581
- Least m such that if a/b < c/d are Farey fractions of order n then there exists k such that a/b < k/m < c/d, k/m reduced.at n=38A009571
- a(0) = 1, a(n) = n^2 + 2 for n > 0.at n=33A010000
- a(0) = 1, a(n) = 9*n^2 + 2 for n>0.at n=11A010002