1205
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 1452
- Proper Divisor Sum (Aliquot Sum)
- 247
- 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
- 960
- Möbius Function
- 1
- Radical
- 1205
- Omega Function (Ω)
- 2
- 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
- 18
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- 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=36A000223
- Numbers m such that Fibonacci(m) ends with m.at n=34A000350
- Expansion of 1/((1-x^2)*(1-x^4)^2*(1-x^6)*(1-x^8)*(1-x^10)) (even powers only).at n=24A001994
- Divisors of 2^24 - 1.at n=37A003532
- Divisors of 2^48 - 1.at n=45A003553
- Expansion of (1 + x - x^5) / (1 - x)^3.at n=44A004120
- a(n) = ceiling(1000*log_10(n)).at n=15A004227
- Number of distinct autocorrelations of binary words of length n.at n=41A005434
- Number of fullerenes with 2n vertices (or carbon atoms).at n=19A007894
- Some permutation of digits is a cube.at n=45A007939
- Noncubes such that some permutation of digits is a cube.at n=35A007940
- Coordination sequence T2 for Zeolite Code LOV.at n=23A008135
- Expansion of (1+x^8)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=43A008769
- Number of 3's in partitions of n into distinct parts.at n=47A015737
- Number of partitions of n into distinct parts, none being 3.at n=45A015745
- Positive integers n such that 2^n == 2^5 (mod n).at n=42A015925
- Pseudoprimes to base 64.at n=43A020192
- Sequence and first differences include all positive integers except 2.at n=43A022443
- a(1) = 3; a(n+1) = a(n)-th composite.at n=18A022451
- a(n) = a(n-1) + b(n-2) for n >= 3, a( ) increasing, given a(1) = 1, a(2) = 3; where b( ) is complement of a( ).at n=44A022940