1840
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 4464
- Proper Divisor Sum (Aliquot Sum)
- 2624
- 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
- 704
- Möbius Function
- 0
- Radical
- 230
- Omega Function (Ω)
- 6
- 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
- 37
- 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
- Number of ways of writing n as a sum of 5 squares.at n=22A000132
- Almost trivalent maps.at n=2A002008
- Theta series of D_5 lattice.at n=11A005930
- Coordination sequence T1 for Zeolite Code ATS.at n=31A008038
- Coordination sequence T1 for Zeolite Code VFI.at n=33A008245
- Coordination sequence T1 for Coesite.at n=23A008267
- Coordination sequence T1 for Keatite.at n=24A009844
- Coordination sequence for FeS2-Marcasite, Fe position.at n=21A009955
- Imaginary Rabbits: imaginary part of a(0)=i; a(1)=-i; a(n) = a(n-1) + i*a(n-2), with i = sqrt(-1).at n=23A014291
- Pisot sequence T(2,5), a(n) = floor(a(n-1)^2/a(n-2)).at n=8A018914
- a(n) = n*(7*n - 1)/2.at n=23A022264
- n-th 8k+1 prime plus n-th 8k+7 prime.at n=36A022761
- Convolution of A023532 and odd numbers.at n=47A023601
- Convolution of (1, p(1), p(2), ...) and composite numbers.at n=12A023627
- Convolution of A014306 (starting 0,0,1,1,0,1,1,1,1,...) and primes.at n=34A023674
- a(n) = Sum_{k=1..n} k*floor( prime(k)/k ).at n=33A024927
- a(n) = sum of the numbers between the two n's in A026370.at n=22A026373
- Number of partitions of n into an even number of parts, the greatest being 6; also, a(n+11) = number of partitions of n+5 into an odd number of parts, each <=6.at n=45A026930
- a(n) = n*(n + 6).at n=40A028560
- Expansion of (theta_3(z)*theta_3(19z) + theta_2(z)*theta_2(19z))^3.at n=33A028643