1803
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2408
- Proper Divisor Sum (Aliquot Sum)
- 605
- 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
- 1200
- Möbius Function
- 1
- Radical
- 1803
- 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
- 42
- 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
- a(n) = floor( Bernoulli(2*n)/(-4*n) ).at n=11A003414
- Divisors of 2^50 - 1.at n=12A003554
- Numbers k such that 4*3^k - 1 is prime.at n=14A005540
- Coordination sequence T9 for Zeolite Code MFI.at n=27A008172
- Expansion of (1+x^12)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=51A008773
- Apply partial sum operator thrice to partition numbers.at n=11A014160
- a(n) = n^2 + 3*n - 1.at n=41A014209
- Number of subsets of { 1, ..., n } containing an A.P. of length 5.at n=13A018790
- Number of solutions to c(1)*prime(3) + ... + c(n)*prime(n+2) = 0, where c(i) = +-1 for i>1, c(1) = 1.at n=19A022900
- Numbers k such that Fibonacci(k) == 2 (mod k).at n=32A023174
- a(n) = least k such that 1+2+...+k >= 1^3 + 2^3 + ... + n^3.at n=49A027924
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 28.at n=12A031526
- Number of binary codes (not necessarily linear) of length n with 3 words.at n=36A034198
- Number of partitions satisfying cn(0,5) + cn(2,5) <= cn(1,5) and cn(0,5) + cn(2,5) <= cn(4,5) and cn(0,5) + cn(3,5) <= cn(1,5) and cn(0,5) + cn(3,5) <= cn(4,5).at n=34A039883
- Number of partitions satisfying 0 < cn(2,5) + cn(3,5).at n=25A039897
- Numbers k such that 0 and 3 occur juxtaposed in the base-10 representation of k but not of k-1.at n=35A043218
- Numbers k such that 0 and 3 occur juxtaposed in the base-10 representation of k but not of k+1.at n=35A043998
- Numbers k such that string 5,4 occurs in the base 7 representation of k but not of k-1.at n=41A044177
- Numbers n such that string 1,3 occurs in the base 8 representation of n but not of n-1.at n=32A044198
- Numbers k such that string 2,3 occurs in the base 9 representation of k but not of k-1.at n=25A044272