7505
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 9600
- Proper Divisor Sum (Aliquot Sum)
- 2095
- 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
- 5616
- Möbius Function
- -1
- Radical
- 7505
- 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
- 176
- 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) = (tau(n^n)+n-1)/n.at n=59A016012
- Denominators of continued fraction convergents to sqrt(874).at n=9A042689
- Numbers n such that 55*2^n-1 is prime.at n=33A050553
- a(n) = n*(n+1)*(n^2+5*n+18)/24.at n=18A051744
- Number of permutations avoiding the patterns {4321, 45132, 45231, 35412, 53412, 45213, 43512, 45312, 456123, 451623, 356124}; number of strong sorting class based on 4321.at n=8A111283
- 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=33A134604
- Triangle T(n, k, j) = T(n-1, k, j) + T(n-1, k-1, j) + (2*j + 1)*prime(j)*T(n-2, k-1, j) with T(2, k, j) = prime(j) and j = 8, read by rows.at n=11A153653
- Triangle T(n, k, j) = T(n-1, k, j) + T(n-1, k-1, j) + (2*j + 1)*prime(j)*T(n-2, k-1, j) with T(2, k, j) = prime(j) and j = 8, read by rows.at n=13A153653
- Triangle A054521 * A157019, where A054521 = an infinite lower triangular matrix and A157019 = a vector [1, 2, 2, 4, 2, 8, 2, 10, 8, ...].at n=46A157031
- Erroneous version of A140763.at n=22A159579
- 5 times centered pentagonal numbers: 5*(5*n^2 + 5*n + 2)/2.at n=24A164015
- Increasing sequence generated by these rules: a(1)=1, and if x is in a then 3x+2 and 4x-3 are in a.at n=43A191139
- G.f.: (1+x^3)/(1-x-x^6).at n=37A193941
- Numbers n for which number of iterations to reach the largest equals number of iterations to reach 1 from the largest in Collatz (3x+1) trajectory of n.at n=21A224303
- Odd numbers n for which the number of iterations to reach the largest equals number of iterations to reach 1 from the largest in Collatz (3x+1) trajectory of n.at n=8A224533
- Number of distinct values of the sum of a*b+a*c+b*c over 2 sets of three a,b,c 0..n integers.at n=36A225269
- Total number of parts in all partitions of n plus the sum of largest parts in all partitions of n plus the number of partitions of n plus n.at n=19A225610
- Number of nX3 0..1 arrays with no element less than a strict majority of its horizontal, vertical, diagonal and antidiagonal neighbors.at n=5A231510
- Number of nX6 0..1 arrays with no element less than a strict majority of its horizontal, vertical, diagonal and antidiagonal neighbors.at n=2A231513
- T(n,k)=Number of nXk 0..1 arrays with no element less than a strict majority of its horizontal, vertical, diagonal and antidiagonal neighbors.at n=30A231515