2481
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 3312
- Proper Divisor Sum (Aliquot Sum)
- 831
- 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
- 1652
- Möbius Function
- 1
- Radical
- 2481
- 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
- 40
- 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 integers with a shortest addition chain of length n.at n=15A003065
- Numbers k such that 4!*(2k-5)!/(k!*(k-1)!) is an integer.at n=20A004784
- 5!(2n-6)!/n!(n-1)! is an integer.at n=25A004785
- Numbers k such that 6!*(2*k-7)!/(k!*(k-1)!) is an integer.at n=4A004786
- Numbers k such that 7!*(2k-8)!/(k!*(k-1)!) is an integer.at n=4A004787
- Centered pentagonal numbers: (5n^2+5n+2)/2; crystal ball sequence for 3.3.3.4.4. planar net.at n=31A005891
- Coordination sequence T3 for Zeolite Code -PAR.at n=35A009857
- Numbers k such that the continued fraction for sqrt(k) has period 52.at n=4A020391
- Numbers k such that Fibonacci(k) == -2 (mod k).at n=39A023163
- Generalized Catalan Numbers x^2*A(x)^2 -(1-x+x^2+x^3+x^4)*A(x) + 1 =0.at n=15A023421
- a(n) = least m such that if r and s in {1/2, 1/5, 1/8, ..., 1/(3n-1)} satisfy r < s, then r < k/m < (k+1)/m < s for some integer k.at n=22A024837
- 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+2)/m < s for some integer k.at n=21A024842
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+4)/m < s for some integer k.at n=16A024847
- Index of 10^n within the sequence of the numbers of the form 2^i*10^j.at n=38A025740
- 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 32.at n=18A031530
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 28 ones.at n=9A031796
- Fractional part of square root of a(n) starts with 8: first term of runs.at n=47A034114
- Growth function (or coordination sequence) of the infinite cubic graph corresponding to the srs net (a(n) = number of nodes at distance n from a fixed node).at n=43A038620
- Denominators of continued fraction convergents to sqrt(309).at n=10A041583
- Numbers whose base-7 representation has exactly 5 runs.at n=21A043620