1837
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2016
- Proper Divisor Sum (Aliquot Sum)
- 179
- 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
- 1660
- Möbius Function
- 1
- Radical
- 1837
- 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
- 130
- 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
- Centered 12-gonal numbers, or centered dodecagonal numbers: numbers of the form 6*k*(k-1) + 1.at n=17A003154
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals rooted at a cell up to rotation and reflection.at n=21A003452
- Numbers k such that k, k+1 and k+2 have the same number of divisors.at n=32A005238
- Number of intersections of diagonals in the interior of a regular n-gon.at n=17A006561
- Numerators of generalized Bernoulli numbers.at n=11A006569
- Expansion of layer susceptibility series for cubic lattice.at n=5A007287
- Coordination sequence T2 for Zeolite Code DDR.at n=27A008072
- Coordination sequence T4 for Zeolite Code HEU.at n=28A008119
- Coordination sequence T2 for Zeolite Code VFI.at n=33A008246
- Year of birth of n-th President of U.S.A.at n=21A008745
- Year of birth of n-th President of U.S.A.at n=23A008745
- If a, b are in the sequence, so is ab+3.at n=44A009302
- Coordination sequence T3 for Zeolite Code -CLO.at n=38A009852
- Coordination sequence T3 for Zeolite Code ZON.at n=30A009921
- Coordination sequence for sigma-CrFe, Position Xc.at n=11A009961
- Numbers k such that the continued fraction for sqrt(k) has period 48.at n=9A020387
- Sum of digits in n-th term of A022482.at n=22A022487
- Conjectured number of irreducible multiple zeta values of depth 10 and weight 2n+28.at n=7A022498
- a(n) = [ (2nd elementary symmetric function of S(n))/(first elementary symmetric function of S(n)) ], where S(n) = {first n+1 positive integers congruent to 2 mod 3}.at n=49A024398
- a(n) = least m such that if r and s in {1/2, 1/4, 1/6, ..., 1/2n} satisfy r < s, then r < k/m < (k+2)/m < s for some integer k.at n=18A024842