2747
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2856
- Proper Divisor Sum (Aliquot Sum)
- 109
- 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
- 2640
- Möbius Function
- 1
- Radical
- 2747
- 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
- 66
- 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
- Sum of the first n primes.at n=38A007504
- Coordination sequence T3 for Zeolite Code -CHI.at n=33A009848
- arcsin(arcsin(arcsin(x)))=x+3/3!*x^3+57/5!*x^5+2747/7!*x^7+249777/9!*x^9...at n=3A012064
- Poincaré series [or Poincare series] for depths of roots in a certain root system.at n=20A019527
- An "extremely strange sequence": a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p dividing [ A*a(n)+B ] and p=2, A=4.001, B=1.2.at n=27A028948
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 51.at n=16A031549
- AND-convolution of squares A000290 with themselves.at n=36A033458
- Coordination sequence T1 for Zeolite Code CFI.at n=34A033599
- Multiplicity of highest weight (or singular) vectors associated with character chi_7 of Monster module.at n=39A034395
- Number of binary rooted trees with n nodes and height exactly 6.at n=17A036595
- Numerators of continued fraction convergents to sqrt(385).at n=9A041730
- Numerators of continued fraction convergents to sqrt(802).at n=4A042546
- a(n)=(s(n)+3)/8, where s(n)=n-th base 8 palindrome that starts with 5.at n=41A043069
- Numbers k such that the string 8,2 occurs in the base 9 representation of k but not of k-1.at n=36A044325
- Numbers n such that string 4,7 occurs in the base 10 representation of n but not of n-1.at n=30A044379
- Numbers n such that string 8,2 occurs in the base 9 representation of n but not of n+1.at n=36A044706
- Numbers n such that string 4,7 occurs in the base 10 representation of n but not of n+1.at n=30A044760
- Numbers having, in base 14, (sum of even run lengths)=(sum of odd run lengths).at n=2A044885
- Numbers whose base-3 representation contains exactly three 0's and four 2's.at n=27A045008
- Numbers whose base-4 representation contains no 1's and exactly four 2's.at n=34A045089