8725
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 10850
- Proper Divisor Sum (Aliquot Sum)
- 2125
- 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
- 6960
- Möbius Function
- 0
- Radical
- 1745
- Omega Function (Ω)
- 3
- 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
- 47
- 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
- no
- Odd
- yes
Appears in sequences
- Discriminants of totally real quartic fields (see comments).at n=31A002769
- Pseudoprimes to base 24.at n=32A020152
- Discriminants of totally real quartic fields.at n=41A023680
- Numbers k such that 5*10^k + R_k + 8 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=11A103007
- Partial sums of orders of finite perfect groups (A060793).at n=13A121513
- Composite numbers of form 8n+5 with all prime factors of form 8m+5.at n=34A175486
- a(n) = n*(14*n - 1).at n=25A195024
- a(1)=2, a(2)=3, for n >= 3, a(n) = 2*(gpf(a(n-1)) + gpf(a(n-2))) + 1, where gpf(n) is the greatest prime factor of n.at n=44A202211
- Least n such that L(n)<-1 and L(n)>L(n-1), where L(k) means the least root of the polynomial p(k,x) defined at A206284, and a(1)=13.at n=12A206443
- a(n) = n*(n^2 + 3*n - 2)/2.at n=25A256857
- Numbers k such that 399*2^k+1 is prime.at n=24A323044
- Terms k of A228058 such that gcd(k - A048250(k), A162296(k) - k) = A162296(k) - k.at n=17A325376
- a(n) = a(n-1) + a(n-3) unless a(n-1) and a(n-3) are both even in which case a(n) = (a(n-1) + a(n-3))/2, with a(0) = a(1) = a(2) = 1.at n=31A341312
- Numbers k for which the 3-adic valuations of k and sigma(k) are equal, and that also satisfy Euler's criterion for odd perfect numbers (see A228058).at n=33A349755
- 31-gonal numbers: a(n) = n*(29*n-27)/2.at n=25A360488
- Odd composites k such that sigma(k) has the same powerful part as k, where sigma is the sum of divisors function.at n=9A386425
- Numbers k satisfying Euler's criterion for odd perfect numbers (A228058), such that sigma(k)+k is also a multiple of 3, and sigma(k) preserves the 3-adic valuation of k, where sigma is the sum of divisors function.at n=33A387162
- Numbers of the form 12*k + 1 that satisfy Euler's condition for odd perfect numbers (A228058).at n=29A387404