1900
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 4340
- Proper Divisor Sum (Aliquot Sum)
- 2440
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 720
- Möbius Function
- 0
- Radical
- 190
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 29
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = floor(n*phi^9), where phi is the golden ratio, A001622.at n=25A004924
- a(n) = round(n*phi^9), where phi is the golden ratio, A001622.at n=25A004944
- Triangular numbers plus quarter squares: n*(n+1)/2 + floor(n^2/4) (i.e., A000217(n) + A002620(n)).at n=50A006578
- Number of primes <= 2^n.at n=14A007053
- Coordination sequence T3 for Zeolite Code AFR.at n=33A008021
- Coordination sequence T4 for Zeolite Code EUO.at n=27A008099
- Aliquot sequence starting at 180.at n=33A008891
- Coordination sequence T5 for Zeolite Code RSN.at n=28A009889
- a(n) = (2*n - 1)*n^2.at n=10A015237
- Expansion of x/(1 - 4*x - 3*x^2).at n=6A015530
- Number of lines through exactly 2 points of an n X n grid of points.at n=10A018809
- Number of lines through exactly 10 points of an n X n grid of points.at n=59A018817
- Numbers n such that n is a substring of its square in base 7 (written in base 10).at n=8A018831
- Squares on infinite chessboard at n moves from center using a {2,3} fairy knight.at n=29A018839
- Numbers whose base-7 representation is the juxtaposition of two identical strings.at n=37A020335
- Number of partitions of n into composite parts.at n=62A023895
- [ Sum{(log(j)-log(i))^2} ], 2 <= i < j <= n.at n=53A025206
- a(n) = dot_product(1,2,...,n)*(5,6,...,n,1,2,3,4).at n=14A026043
- dot product (n,n-1,...2,1).(3,4,...,n,1,2).at n=17A026054
- a(n) = dot_product(n,n-1,...2,1)*(5,6,...,n,1,2,3,4).at n=14A026060