3979
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
- 4176
- Proper Divisor Sum (Aliquot Sum)
- 197
- 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
- 3784
- Möbius Function
- 1
- Radical
- 3979
- 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
- 95
- 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
- Number of centered trees with n nodes.at n=15A000676
- Number of elements in Z[ omega ] whose 'smallest algorithm' is <= n, where omega^2 = -omega - 1.at n=6A006458
- Coordination sequence T2 for Zeolite Code EUO.at n=39A008097
- Numbers k such that the continued fraction for sqrt(k) has period 46.at n=29A020385
- a(n) = n*(15*n + 1)/2.at n=23A022273
- Expansion of (1+x^2-x^3)/(1-x)^4.at n=26A027378
- Number of partitions of n into parts not of form 4k+2, 20k, 20k+9 or 20k-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 4 are greater than 1 when the smallest part is odd and greater than 2 when the smallest part is even.at n=41A036028
- Denominators of continued fraction convergents to sqrt(567).at n=6A042087
- Numerators of continued fraction convergents to sqrt(659).at n=4A042266
- Numbers whose base-5 representation contains exactly three 1's and two 4's.at n=22A045261
- a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = n - 1 - 2^p and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1, a(2) = 3, and a(3) = 2.at n=12A049970
- Sum of digits = 7 times number of digits.at n=41A061424
- Numbers k such that floor(k*e) is a square.at n=38A062268
- Triangle read by rows, T(n,k) = T(n-1,k) + T(n-2,k) + T(n-1,k-1) + T(n-2,k-1) and T(0,0) = 1.at n=58A063967
- Prefixing, suffixing or inserting a 9 in the number anywhere gives a prime.at n=24A069833
- Sum of the n-th row of A077339.at n=12A081929
- Number of square plane partitions of n.at n=28A089299
- Numbers n such that n, n+2, n+4, n+6 are semiprimes.at n=36A092126
- a(n) = Sum_{k=1..n} (lcm(n,n-1,...,n-k+2,n-k+1)/lcm(1,2,...,k)).at n=12A093431
- a(n) = (27*n^2 + 9*n + 2)/2.at n=17A093485