3990
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
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 11520
- Proper Divisor Sum (Aliquot Sum)
- 7530
- 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
- 864
- Möbius Function
- -1
- Radical
- 3990
- Omega Function (Ω)
- 5
- Little Omega Function (ω)
- 5
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 51
- 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
- Class numbers associated with terms of A001990.at n=24A001991
- Class numbers associated with terms of A001990.at n=26A001991
- Class numbers associated with terms of A001990.at n=25A001991
- Coefficients for step-by-step integration.at n=3A002403
- a(n) = n*(3^n - 2^n).at n=6A004142
- a(n) is the smallest positive integer a for which there is an identity of the form a*n*x = Sum_{i=1..m} ai*gi(x)^n where a1, ..., am are in Z and g1(x), ..., gm(x) are in Z[x].at n=39A005729
- Coordination sequence T1 for Zeolite Code ERI and OFF.at n=46A008093
- Coefficient of x^n in (Product_{m=1..n}(1-x^m))^n.at n=15A008705
- Expansion of cos(log(1+x)/cos(x)).at n=7A009032
- Expansion of Product_{k>=1} (1 - x^k)^15.at n=15A010822
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 4.at n=22A013592
- Expansion of 1/((1-3*x)*(1-7*x)*(1-11*x)).at n=3A018054
- a(n) = n*(n+1)*(n+2)/2.at n=19A027480
- Least term in period of continued fraction for sqrt(n) is 6.at n=23A031430
- Number of ternary codes of length 7 with n words.at n=4A034219
- Number of ternary codes (not necessarily linear) of length n with 4 words.at n=6A034224
- a(n) = n*(2*n-1)*(2*n+1).at n=10A035328
- Number of partitions of n into parts not of form 4k+2, 24k, 24k+9 or 24k-9. Also number of partitions in which no odd part is repeated, with at most 4 parts of size less than or equal to 2 and where differences between parts at distance 5 are greater than 1 when the smallest part is odd and greater than 2 when the smallest part is even.at n=41A036033
- Sparsely totient numbers; numbers n such that m > n implies phi(m) > phi(n).at n=35A036913
- Coordination sequence T10 for Zeolite Code STT.at n=42A038422