2757
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3680
- Proper Divisor Sum (Aliquot Sum)
- 923
- 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
- 1836
- Möbius Function
- 1
- Radical
- 2757
- 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
- 128
- 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
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=29A000092
- A Fielder sequence.at n=12A001643
- a(n) = a(n-1) + a(n-2) + a(n-3), a(0)=3, a(1)=1, a(2)=3.at n=13A001644
- a(n) = 4^floor(n/2)*a(n-1) - a(n-2), for n >= 2, with a(0) = a(1) = 1.at n=5A003115
- Coordination sequence T1 for Zeolite Code PHI.at n=38A008227
- Coordination sequence T2 for Zeolite Code PHI.at n=38A008228
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=42A013583
- a(n) = n*(n-1) + (n-2)*(n-3) + ... + 1*0 + 1 for n odd; otherwise, a(n) = n*(n-1) + (n-2)*(n-3) + ... + 2*1.at n=24A014112
- Numbers k giving rise to prime quadruples (30k+11, 30k+13, 30k+17, 30k+19).at n=33A014561
- Numbers k such that Fibonacci(k) == 2 (mod k).at n=44A023174
- Convolution of Lucas numbers and A023533.at n=15A023623
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=28A024835
- 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 34.at n=25A031532
- Coordination sequence T4 for Zeolite Code SBS.at n=42A033611
- Coordination sequence T3 for Zeolite Code AWO.at n=36A038405
- Numbers n such that string 0,3 occurs in the base 9 representation of n but not of n-1.at n=36A044254
- Numbers n such that string 5,7 occurs in the base 10 representation of n but not of n-1.at n=30A044389
- Numbers n such that string 0,3 occurs in the base 9 representation of n but not of n+1.at n=36A044635
- Numbers n such that string 5,7 occurs in the base 10 representation of n but not of n+1.at n=30A044770
- Numbers having, in base 14, (sum of even run lengths)=(sum of odd run lengths).at n=12A044885