2565
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 4800
- Proper Divisor Sum (Aliquot Sum)
- 2235
- 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
- 1296
- Möbius Function
- 0
- Radical
- 285
- Omega Function (Ω)
- 5
- 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
- 53
- 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
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); A000092 gives values of n where |P(n)| sets a new record; sequence gives (nearest integer to, I believe) P(A000092(n)).at n=45A000223
- a(n) = a(n-1) + 2*a(n-3) with a(0)=a(1)=1, a(2)=3.at n=15A003229
- Sum of 10 positive 9th powers.at n=5A003399
- a(n) = 1000*log(n) rounded to the nearest integer.at n=12A004241
- a(n) = ceiling(1000*log(n)).at n=12A004242
- Coordination sequence T5 for Zeolite Code BOG.at n=36A008053
- Coordination sequence T2 for Zeolite Code LTL.at n=37A008139
- a(n) = b(n) - c(n) where b(n) is the n-th Fibonacci number greater than 2 and c(n) is the n-th number not in sequence b( ).at n=14A014251
- Numbers k such that k | 14^k + 1.at n=38A015965
- Expansion of 1/(1-x^6-x^7-x^8-x^9-x^10-x^11-x^12-x^13-x^14).at n=42A017854
- a(n) = n*(7*n + 1)/2.at n=27A022265
- Number of 6's in all partitions of n.at n=30A024790
- Number of n-move bishop paths on 8x8 board from given corner to opposite corner.at n=5A025594
- Expansion of 1/((1-x)^2(1-x^2)(1-x^3)(1-x^5)) in powers of x.at n=31A028291
- Numbers k that divide the (right) concatenation of all numbers <= k written in base 19 (most significant digit on left).at n=34A029464
- Every run of digits of n in base 4 has length 2.at n=21A033002
- Sort then Add, a(1) =9.at n=9A033896
- Sort then Add, a(1)=27.at n=7A033903
- Divide odd numbers into groups with prime(n) elements and add together.at n=7A034960
- Related to 9-factorial numbers A045756.at n=2A035097