3997
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4576
- Proper Divisor Sum (Aliquot Sum)
- 579
- 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
- 3420
- Möbius Function
- 1
- Radical
- 3997
- 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
- 51
- 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
- Class numbers of quadratic fields.at n=12A001985
- Hex (or centered hexagonal) numbers: 3*n*(n+1)+1 (crystal ball sequence for hexagonal lattice).at n=36A003215
- Numbers k such that 4!*(2k-5)!/(k!*(k-1)!) is an integer.at n=40A004784
- Coordination sequence T1 for Zeolite Code iRON.at n=44A009881
- a(n) = floor(n*(n-1)*(n-2)/16).at n=41A011898
- [ (4th elementary symmetric function of S(n))/(2nd elementary symmetric function of S(n)) ], where S(n) = {first n+3 positive integers congruent to 1 mod 3}.at n=10A024223
- a(n) = least m such that if r and s in {1/3, 1/6, 1/9,..., 1/3n} satisfy r < s, then r < k/m < s for some integer k.at n=41A024824
- a(n) = least m such that if r and s in {1/1, 1/2, 1/3, ..., 1/n} satisfy r < s, then r < k/m < (k+2)/m < s for some integer k.at n=38A024840
- A B_2 sequence: a(n) is the least value such that sequence increases and pairwise sums of elements are all distinct.at n=45A025582
- Squarefree n such that Q(sqrt(n)) has class number 5.at n=28A029705
- Exactly 5 digits from {1,2,3,4,5,6,7,8,9} can precede a(n) to form a prime.at n=36A032695
- Number of partitions satisfying (cn(1,5) <= cn(2,5) and cn(1,5) <= cn(3,5) and cn(4,5) <= cn(2,5) and cn(4,5) <= cn(3,5)).at n=38A036803
- Coordination sequence T2 for Zeolite Code STT.at n=42A038423
- Numbers ending with '7' that are the difference of two positive cubes.at n=24A038862
- Numbers whose base-7 representation contains exactly three 4's.at n=36A043411
- Numbers whose base-5 representation contains exactly three 1's and two 4's.at n=26A045261
- Sum of digits = 7 times number of digits.at n=43A061424
- Composite and every divisor (except 1) contains the digit 7.at n=15A062676
- Numerators of coefficients in Airy-type asymptotic expansion.at n=5A069242
- Numbers k such that the number of primes between k and 2k (inclusive) is equal to the number of primes between k and reverse(k) (inclusive).at n=17A074814