7041
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 9392
- Proper Divisor Sum (Aliquot Sum)
- 2351
- 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
- 4692
- Möbius Function
- 1
- Radical
- 7041
- 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
- 57
- 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
- Expansion of e.g.f.: exp(sinh(x))/cosh(x).at n=9A009226
- Expansion of sin(sin(x))/cos(x).at n=4A009479
- Numbers k such that the continued fraction for sqrt(k) has period 94.at n=13A020433
- a(n) = T(2n,n-3), T given by A026725.at n=5A026842
- a(n) = T(2n+1,n+4), T given by A026725.at n=5A026846
- a(n) = T(2n,n-3), T given by A026736.at n=5A026849
- Expansion of (1+x^2-x^3)/(1-x)^4.at n=32A027378
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 50 ones.at n=20A031818
- a(n)=(s(n)+3)/10, where s(n)=n-th base 10 palindrome that starts with 7.at n=26A043086
- a(1) = 7; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=46A046257
- Average of terms of n-th row of A077321.at n=28A077325
- Where records occur in A079387.at n=14A079389
- Special values of the hypergeometric function 3F1: a(n) = binomial(n,2) * hypergeom([1,-n+1,-n+2],[3],1).at n=5A080996
- Number of ways to tile an n X n board having a black border with the following 1 X 1 tiles: bbbb, bbww, wbbw, bwwb, wwbb, where the colors are read clockwise around each tile.at n=5A086832
- n times n+7 gives the concatenation of two numbers m and m+6.at n=0A116332
- Start with 1 and repeatedly reverse the digits and add 50 to get the next term.at n=40A118147
- Semiprimes s such that s-/+2 are primes.at n=37A125215
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (0, 1, 0), (1, 0, 1), (1, 1, -1)}.at n=7A150288
- Semiprimes q such that q^2-4 and q^2+4 are also semiprimes.at n=13A173084
- Number of (n+1) X 2 0..2 arrays with the number of clockwise edge increases in every 2 X 2 subblock equal to one.at n=3A206047