2824
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
- 8
- Divisor Sum
- 5310
- Proper Divisor Sum (Aliquot Sum)
- 2486
- 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
- 1408
- Möbius Function
- 0
- Radical
- 706
- 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
- 128
- 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
- High temperature series in v = tanh(J/kT) for residual correlation function (correction to susceptibility) for the spin-1/2 Ising model on square lattice.at n=7A002907
- Numbers k such that k^4 can be written as a sum of four positive 4th powers.at n=13A003294
- Number of matrix bundles of codimension n (Euler transform of A001156).at n=17A007864
- Coordination sequence T3 for Zeolite Code VSV.at n=33A009916
- a(n) = floor( n*(n-1)*(n-2)*(n-3)/26 ).at n=18A011936
- Number of partitions of n into distinct parts, none being 7.at n=51A015754
- Numbers k such that phi(k) + 9 | sigma(k + 9).at n=29A015788
- Ordered sequence of distinct terms of the form floor(exp(i) * floor(exp(j))), i,j >= 0.at n=29A022765
- Numbers k such that Fib(k) == -21 (mod k).at n=28A023168
- Triangular array T read by rows (9-diamondization of Pascal's triangle). Step 1: t(n,k) = sum of 9 entries in diamond-shaped subarray of Pascal's triangle having vertices C(n,k), C(n+4,k+2), C(n+2,k), C(n+2,k+2). Step 2: T(n,k) = t(n,k) - t(0,0) + 1.at n=40A026907
- a(n) = A026907(2*n, n).at n=4A026908
- T(n,[ n/2 ]), T given by A026907.at n=8A026914
- Expansion of (theta_3(z)*theta_3(23z)+theta_2(z)*theta_2(23z))^4.at n=18A028660
- Numbers having period-6 5-digitized sequences.at n=20A031190
- Least term in period of continued fraction for sqrt(n) is 7.at n=7A031431
- 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 13.at n=25A031511
- Numbers having three 7's in base 9.at n=3A043483
- Numbers n such that string 1,0 occurs in the base 8 representation of n but not of n-1.at n=43A044195
- Numbers k such that the string 2,4 occurs in the base 10 representation of k but not of k-1.at n=31A044356
- Numbers n such that string 2,4 occurs in the base 10 representation of n but not of n+1.at n=31A044737