4365
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 7644
- Proper Divisor Sum (Aliquot Sum)
- 3279
- 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
- 2304
- Möbius Function
- 0
- Radical
- 1455
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 46
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- 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
- a(0) = 1, a(1) = 0, a(2) = -1; for n >= 3, a(n) = - a(n-2) + Sum_{ primes p with 3 <= p <= n} a(n-p).at n=53A002121
- Coordination sequence T1 for Zeolite Code LAU.at n=47A008124
- Coordination sequence T2 for Zeolite Code VET.at n=40A009903
- Pseudoprimes to base 98.at n=36A020226
- First row of spectral array W(sqrt(3/2)).at n=9A022163
- a(n) = n*(27*n - 1)/2.at n=18A022284
- a(n) = T(2n-1,n-2), T given by A026758.at n=5A026763
- a(n+1) = Sum_{k=0..sqrt(n)} a(k) * a(n-k).at n=13A030041
- Number of partitions of n into parts not of form 4k+2, 16k, 16k+3 or 16k-3.at n=49A036021
- Conjecturally, a power of 2 written in base 3 cannot have this many 2's.at n=31A036463
- Positive numbers having the same set of digits in base 7 and base 8.at n=35A037438
- a(n) = Sum_{k=1..n, gcd(n,k) = 1} k^2.at n=26A053818
- Number of n-celled polyominoes without holes, symmetric about axis 2.at n=30A056880
- Numbers k that, when expressed in base 4 and then interpreted in base 8, give a multiple of k.at n=35A062923
- Numbers whose decimal representations consist of nested and /or concatenated ordered pairs 0-9, 1-8, 2-7, 3-6 and 4-5.at n=37A065751
- Number of identity (asymmetric) bracelets (or necklaces) with n red and blue beads such that the beads switch colors when bracelet is turned over.at n=6A066316
- Numbers k that divide 2^(k+3) - 1.at n=26A069927
- a(n) is the smallest number k such that A073813(k) = prime(n).at n=19A073814
- Expansion of 1/sqrt((1-x)^2-8x^4).at n=13A098483
- Triangle, read by rows, of coefficients in powers of e.g.f. for A100065 such that, for each row n>=0, Sum_{k=0..n} T(n,k)/k! = [exp(n)] (integer floor of e^n).at n=20A100064