2723
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 14
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3120
- Proper Divisor Sum (Aliquot Sum)
- 397
- 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
- 2328
- Möbius Function
- 1
- Radical
- 2723
- 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
- 53
- 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
- Number of board-pair-pile polyominoes with n cells.at n=7A001170
- Number of strictly 2-dimensional fixed polyominoes with n cells.at n=7A006762
- Coordination sequence T1 for Zeolite Code AFI.at n=36A008014
- Coordination sequence T4 for Zeolite Code BOG.at n=37A008052
- Expansion of e.g.f.: cos(log(1 + sinh(x))).at n=7A009020
- Expansion of log(1+tanh(x)/cos(x)).at n=7A009400
- a(n) = Sum_{k=1..n} k*phi(k).at n=22A011755
- arctanh(sec(x)*tanh(x))=x+3/3!*x^3+65/5!*x^5+2723/7!*x^7...at n=3A012837
- E.g.f.: log(tanh(x)+cos(x))=x-2/2!*x^2+3/3!*x^3-12/4!*x^4+65/5!*x^5...at n=7A013152
- Coordination sequence T8 for Zeolite Code TER.at n=35A016440
- Self-convolution of composite numbers.at n=14A023648
- Numbers k such that in k and k^2 the parity of digits alternates.at n=24A030153
- Multiplicity of highest weight (or singular) vectors associated with character chi_102 of Monster module.at n=43A034490
- Number of different values of i^2 + j^2 + k^2 for i,j,k in [ 0,n ] (or [ -n,n ]).at n=38A034966
- Number of partitions satisfying (cn(0,5) = cn(1,5) = cn(4,5) and cn(0,5) <= cn(2,5) and cn(0,5) <= cn(3,5)).at n=50A036824
- Numbers n such that sigma(n) - n = {number of primes <= n}.at n=5A037172
- Numbers k such that us(k) = primepi(k), where us(k) is the sum of the aliquot unitary divisors of k (A034460), and primepi(k) is the number of primes <= k (A000720).at n=7A037176
- a(n)=(s(n)+3)/8, where s(n)=n-th base 8 palindrome that starts with 5.at n=38A043069
- Numbers n such that string 5,5 occurs in the base 9 representation of n but not of n-1.at n=33A044301
- Numbers n such that string 2,3 occurs in the base 10 representation of n but not of n-1.at n=30A044355