1866
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3744
- Proper Divisor Sum (Aliquot Sum)
- 1878
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 620
- Möbius Function
- -1
- Radical
- 1866
- Omega Function (Ω)
- 3
- 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
- 86
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Generalized class numbers c_(n,1).at n=25A000233
- Number of plane partitions of n with at most two rows.at n=16A000990
- Representation degeneracies for Neveu-Schwarz strings.at n=19A005295
- a(n) = 3 + n/2 + 7*n^2/2.at n=23A006124
- Coordination sequence T1 for feldspar.at n=29A008254
- Coordination sequence T1 for Zeolite Code iRON.at n=30A009881
- Coordination sequence T1 for Zeolite Code VET.at n=26A009902
- Number of 5's in all the partitions of n into distinct parts.at n=52A015740
- Number of partitions of n into distinct parts, none being 5.at n=48A015750
- Number of partitions of n into distinct parts, none being 8.at n=47A015755
- Convolution of A023532 and primes.at n=35A023606
- a(n) = T(n,[ n/2 ]), where T is the array defined in A025564.at n=11A025575
- Number of ways of placing n labeled balls into n unlabeled (but 3-colored) boxes.at n=5A027710
- [ exp(20/21)*n! ].at n=5A030840
- Least term in period of continued fraction for sqrt(n) is 5.at n=10A031429
- 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 14.at n=48A031512
- Numbers with exactly five distinct base-6 digits.at n=34A031983
- Grundy function for turn-at-most-4-coins game.at n=37A033623
- Number of partitions of n such that cn(1,5) < cn(0,5) = cn(2,5) <= cn(3,5) = cn(4,5).at n=63A036859
- Denominators of continued fraction convergents to sqrt(251).at n=7A041471