2761
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3024
- Proper Divisor Sum (Aliquot Sum)
- 263
- 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
- 2500
- Möbius Function
- 1
- Radical
- 2761
- 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
- Squares written in base 8.at n=38A002441
- Divisors of 2^50 - 1.at n=13A003554
- Number of permutations in S_n with longest increasing subsequence of length <= 3 (i.e., 1234-avoiding permutations); vexillary permutations (i.e., 2143-avoiding).at n=7A005802
- a(n) = 3 + n/2 + 7*n^2/2.at n=28A006124
- Number of irreducible positions of size n in Montreal solitaire.at n=7A007076
- Crystal ball sequence for planar net 4.8.8.at n=45A008577
- a(n) = floor(n*(n-1)*(n-2)/13).at n=34A011895
- Positive integers n such that 2^n == 2^11 (mod n).at n=43A015935
- Expansion of 1/(1 - x^10 - x^11 - ...).at n=59A017904
- Pseudoprimes to base 20.at n=16A020148
- Pseudoprimes to base 32.at n=34A020160
- Strong pseudoprimes to base 20.at n=5A020246
- Strong pseudoprimes to base 32.at n=11A020258
- Numbers k such that the continued fraction for sqrt(k) has period 66.at n=5A020405
- Numbers k such that Fibonacci(k) == 89 (mod k).at n=35A023182
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A023532, t = (1, p(1), p(2), ...).at n=47A024369
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A023532, t = (primes).at n=46A024377
- Duplicate of A024377.at n=46A025069
- Triangle read by rows: square of the lower triangular mean matrix.at n=48A027446
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 22 ones.at n=29A031790