7705
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9792
- Proper Divisor Sum (Aliquot Sum)
- 2087
- 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
- 5808
- Möbius Function
- -1
- Radical
- 7705
- Omega Function (Ω)
- 3
- Little Omega Function (ω)
- 3
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
- 145
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Base-9 palindromes that start with 1.at n=34A043028
- Numbers having four 1's in base 9.at n=22A043460
- a(n)=T(n,n), array T as in A049735.at n=35A049740
- Start with 1 and repeatedly reverse the digits and add 42 to get the next term.at n=27A118075
- Numbers (excluding primes and powers of primes) such that the square mean of their prime factors is a prime (where the square mean of c and d is sqrt((c^2+d^2)/2)).at n=34A134604
- Row sums of triangle A143102.at n=27A143103
- 5 times octagonal numbers: a(n) = 5*n*(3*n-2).at n=23A153795
- Sum of all numbers from tau(n) to sigma(n).at n=47A162907
- Smith numbers of order 2.at n=35A174460
- Triangle read by rows: T(n,k) = 2 - (1 + k)^k + (1 + n)^n - (1 - k + n)^(n - k).at n=17A176392
- Triangle read by rows: T(n,k) = 2 - (1 + k)^k + (1 + n)^n - (1 - k + n)^(n - k).at n=18A176392
- a(n) = n*(14*n + 13).at n=23A195028
- Number of lower triangles of an n X n 0..4 array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.at n=3A195228
- T(n,k)is the number of lower triangles of an n X n 0..k array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.at n=24A195232
- Number of lower triangles of a 4 X 4 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by one or less.at n=3A195234
- a(n) = 6*n^2 + 10*n + 5.at n=35A201279
- Sum of distinct residues of all factorials mod 2^n.at n=11A210337
- Fundamental discriminants of real quadratic number fields with class number 10.at n=12A218160
- Smallest k such that k^2 is a concatenation of two numbers x and y where y = x + n^2 and x and y have the same number of digits.at n=32A236383
- Molien series for invariants of finite Coxeter group A_7.at n=61A266776