7565
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9720
- Proper Divisor Sum (Aliquot Sum)
- 2155
- 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
- 5632
- Möbius Function
- -1
- Radical
- 7565
- 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
- 39
- 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
- a(n) = (6*n+1)*(6*n+5).at n=14A001513
- a(n) = (4*n+1)*(4*n+5).at n=21A003185
- Convolution of natural numbers with (1, p(1), p(2), ... ), where p(k) is the k-th prime.at n=24A023538
- a(n) = least m such that if r and s in {1/1, 1/3, 1/5, ..., 1/(2n-1)} satisfy r < s, then r < k/m < (k+3)/m < s for some integer k.at n=32A024844
- Numbers that are the sum of 2 nonzero squares in exactly 4 ways.at n=43A025287
- Least k such that the first k terms of A006928 contain n more 2's than 1's.at n=8A025507
- Numbers n such that A048767(n+1)=A048767(n).at n=13A048769
- McKay-Thompson series of class 31A for Monster.at n=33A058628
- a(n) = (2*n-1)^2 + (2*n)^2.at n=30A060820
- Numbers n such that phi(3n-1) = sigma(n).at n=38A067232
- Numbers n such that sigma(n)=phi(n*bigomega(n)-1).at n=23A067877
- Numbers k such that sigma(k) = phi(k*omega(k)-1).at n=34A067878
- Numbers k that divide 2^(k+3) - 1.at n=35A069927
- Numbers m such that [A070080(m), A070081(m), A070082(m)] is an acute scalene integer triangle with prime side lengths.at n=19A070123
- a(n) = smallest multiple of prime(n) such that a(n) +1 is a multiple of prime(n+1).at n=23A077338
- a(n) = (2*n+5)*(2*n+1).at n=42A078371
- a(n) = 8*n^2 - 4*n + 1.at n=31A080856
- Number of Motzkin paths of length n with no level steps at even level.at n=14A090345
- Numbers m that are the hypotenuse of exactly 13 distinct integer-sided right triangles, i.e., m^2 can be written as a sum of two squares in 13 ways.at n=36A097102
- Numbers whose set of base 6 digits is {0,5}.at n=25A097252