2117
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
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2220
- Proper Divisor Sum (Aliquot Sum)
- 103
- 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
- 2016
- Möbius Function
- 1
- Radical
- 2117
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 32
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = least m such that if a/b < c/d where a,b,c,d are integers in [0,n], then a/b < k/m < c/d for some integer k.at n=52A001000
- a(n) = n^2 + 1.at n=46A002522
- Number of solid partitions of n supported on graph of cube.at n=17A003404
- a(n) = n*(5*n+1)/2.at n=29A005475
- If a, b are in the sequence, so is ab+3.at n=49A009302
- Coordination sequence T3 for Zeolite Code VET.at n=28A009904
- Pisot sequence E(14,23), a(n) = floor( a(n-1)^2/a(n-2)+1/2 ).at n=10A010902
- a(n) = floor( n*(n-1)*(n-2)/28 ).at n=40A011910
- Coordination sequence T3 for Zeolite Code SAO.at n=36A019573
- Pseudoprimes to base 46.at n=31A020174
- Strong pseudoprimes to base 46.at n=10A020272
- a(n) = a(n-1) + a(n-2) + 1 for n>1, a(0)=0, a(1)=4.at n=14A022309
- Prefix primes in base 8 (written in base 8).at n=29A024768
- a(n) = least m such that if r and s in {1/4, 1/8, 1/12,..., 1/4n} satisfy r < s, then r < k/m < s for some integer k.at n=26A024825
- Least m such that if r and s in {Pi/2 - atn(h): h = 1,2,...,n} satisfy r < s, then r < k/m < s for some integer k.at n=51A024832
- a(n) = sum of the numbers between the two n's in A026276.at n=42A026279
- a(n) = least k such that 1+2+...+k >= E{1,2,...,n}, where E is the 3rd elementary symmetric function.at n=19A027917
- a(n) = Sum_{d|n} phi(d)^2.at n=46A029939
- Positions of record values in A030777.at n=41A030782
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 92.at n=0A031680