2792
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 5250
- Proper Divisor Sum (Aliquot Sum)
- 2458
- 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
- 1392
- Möbius Function
- 0
- Radical
- 698
- Omega Function (Ω)
- 4
- 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
- 35
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Coordination sequence T6 for Zeolite Code MEL.at n=34A008155
- Coordination sequence T5 for Zeolite Code NON.at n=32A008216
- Numbers k such that phi(k) + 9 | sigma(k + 9).at n=28A015788
- Numbers k such that Fib(k) == 21 (mod k).at n=20A023179
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = A001950 (upper Wythoff sequence).at n=21A024864
- Coordination sequence T5 for Zeolite Code MWW.at n=35A024990
- Expansion of (theta_3(z)*theta_3(11z) + theta_2(z)*theta_2(11z))^4.at n=11A028612
- Expansion of (theta_3(z)*theta_3(19z) + theta_2(z)*theta_2(19z))^3.at n=48A028643
- 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 25.at n=19A031523
- Numbers whose base-14 representation has exactly 4 runs.at n=31A043665
- Numbers n such that string 4,2 occurs in the base 9 representation of n but not of n-1.at n=38A044289
- Numbers n such that string 9,2 occurs in the base 10 representation of n but not of n-1.at n=29A044424
- Numbers n such that string 4,2 occurs in the base 9 representation of n but not of n+1.at n=38A044670
- Numbers k such that string 9,2 occurs in the base 10 representation of k but not of k+1.at n=29A044805
- Handsome numbers (A007532) representable in exactly two distinct ways (counting different powers of duplicated digits as distinct).at n=43A050241
- Discriminants of real quadratic number fields K with class number 2 such that the Hilbert class field of K is K(sqrt(2)).at n=44A052476
- a(n) = Sum_{k=1..n} sigma(k)*2^(n-k) where sigma(k) = A000203(k) is the sum of divisors of k.at n=9A066767
- Simple rewriting of binary expansion of n resulting A014486-codes for rooted binary trees with height equal to number of internal vertices. (Binary trees where at each internal vertex at least the other child is leaf).at n=38A071162
- a(n) = smallest positive integer that cannot be obtained using the number n at most n times and the operations +, -, *, /, where intermediate subexpressions must be integers.at n=12A071848
- Maximum number of regions into which the plane is divided by n triangles.at n=31A077588