1688
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3180
- Proper Divisor Sum (Aliquot Sum)
- 1492
- 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
- 840
- Möbius Function
- 0
- Radical
- 422
- 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
- 42
- 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
- a(n) = n + n*(n-1)*(n-2)*(n-3).at n=8A001094
- a(n) = n^2 + prime(n).at n=38A004232
- Number of restricted 3 X 3 matrices with row and column sums n.at n=27A005045
- Truncated tetrahedral numbers: a(n) = (1/6)*(n+1)*(23*n^2 + 19*n + 6).at n=7A005906
- Expansion of eta(q^10)^12/(eta(q^2)^4*eta(q^5)^8) in powers of q.at n=14A006710
- Expansion of e.g.f. exp(log(1+x)^2).at n=6A009199
- Expansion of exp(x/cos(x)).at n=7A009300
- Coordination sequence T4 for Zeolite Code -CHI.at n=26A009849
- Numbers k such that phi(k) + 9 | sigma(k + 9).at n=21A015788
- Expansion of 1/((1-3*x)*(1-5*x)*(1-8*x)).at n=3A017521
- Terms of A001273 with trailing 9's stripped (at n=13 term becomes periodic with period 49).at n=46A018785
- Irreducible quadruple Euler sums of weight 2n+10 (verified for n <= 14).at n=43A019449
- Number of 1's in n-th term of A007651.at n=28A022466
- Place where n-th 1 occurs in A007336.at n=48A022775
- Numbers k such that Fib(k) == 21 (mod k).at n=15A023179
- Derivative of log of A007360.at n=34A023892
- a(n) = position of n^3 + (n+1)^3 + (n+2)^3 in A003072.at n=15A024972
- Numbers that are the sum of 4 distinct nonzero squares in exactly 10 ways.at n=45A025385
- Index of 7^n within the sequence of the numbers of the form 2^i*7^j.at n=34A025720
- Number of labeled chain graphs.at n=3A026865