8525
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 11904
- Proper Divisor Sum (Aliquot Sum)
- 3379
- 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
- 6000
- Möbius Function
- 0
- Radical
- 1705
- Omega Function (Ω)
- 4
- 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
- 78
- 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=30A002769
- Divisors of 2^20 - 1.at n=35A003529
- Discriminants of totally real quartic fields.at n=40A023680
- Numbers in which 0,1,2,3,4,5 all occur in base 6.at n=6A031947
- Numbers k that divide 7^k + 3^k.at n=23A045586
- a(n) = Sum_{i=0..n} A047080(i,n-i).at n=22A047084
- Digitally balanced numbers in base 6: equal numbers of 0's, 1's, ..., 5's.at n=6A049357
- a(n)^2 is a square whose digits occur with an equal minimum frequency of 2.at n=36A052049
- a(n) = (1/6)*(2*n - 3)*(n + 2)*(n + 1).at n=31A058373
- Numbers k > 1 such that, in base 4, k and k^2 contain the same digits in the same proportion.at n=27A061658
- a(n) = (7^n + 3^n)/2.at n=5A081336
- Square number array read by antidiagonals.at n=50A084061
- First superdiagonal of number array A084061.at n=5A084095
- Fifth row of number array A084061.at n=5A084096
- Numbers for which the sum of the digits is the square root of the product of their digits.at n=20A117720
- Numbers of the form x^5 + 10*x^3*y^2 + 5*x*y^4 (where x,y are integers).at n=19A135794
- Numbers k such that k and k^2 use only the digits 2, 5, 6, 7 and 8.at n=21A137111
- 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, 1), (-1, 0, 1), (0, 0, 1), (1, 0, -1), (1, 1, 0)}.at n=7A150552
- G.f.: A(x) = F(x*G(x)^2) where F(x) = G(x*F(x)) = 1 + x*F(x)^3 is the g.f. of A001764 and G(x) = F(x/G(x)) = 1 + x*G(x)^2 is the g.f. of A000108 (Catalan).at n=6A153391
- a(n) = (-1)^n*n*(n+1)*(2*n-5)/6.at n=29A167386