4045
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4860
- Proper Divisor Sum (Aliquot Sum)
- 815
- 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
- 3232
- Möbius Function
- 1
- Radical
- 4045
- 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
- 64
- 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
- Coordination sequence for MgNi2, Position Ni3.at n=16A009934
- n written in fractional base 8/4.at n=45A024646
- a(n) = (d(n)-r(n))/2, where d = A026049 and r is the periodic sequence with fundamental period (1,0,0,1).at n=24A026050
- Lucky numbers with size of gaps equal to 18 (lower terms).at n=23A031900
- "AGK" (ordered, elements, unlabeled) transform of 2,1,1,1,...at n=17A032024
- Concatenation of n and n + 5 or {n,n+5}.at n=39A032610
- Lucky numbers that are decimal concatenations of n with n + 5.at n=4A032655
- Coordination sequence T1 for Zeolite Code ISV.at n=44A047958
- Sum of remainders when n-th prime is divided by all preceding integers.at n=35A050482
- Expansion of (1-x)/(1-2*x-x^3+x^4).at n=12A052540
- Positions in decimal expansion of Pi where next prime begins.at n=37A053013
- Sum of numbers in range 10*n to 10*n+9.at n=40A053743
- Number of primes in the interval [prime(n), prime(n)^2].at n=44A054272
- Regard A064413 as giving a permutation of the positive integers; sequence gives second infinite cycle, beginning at its smallest term, 73.at n=38A064667
- a(n) is the smallest k such that (k^3 + 1)/(n^3 + 1) is an integer > 1.at n=32A065964
- a(n) is the unique positive integer m which has a self-conjugate partition whose parts are the first n primes.at n=26A067773
- Numbers that define integer Heronian triangles [a(n), prime(a(n)), A068968(n)] with area A068969(n).at n=25A068967
- Sum of n-th row of triangle in A082196.at n=18A082199
- a(n)=60*sum(1<=i<=j<=k<=n,i^2*j/k).at n=4A088942
- Lower triangular matrix T, read by rows, such that T(n,0) = 1 and T(n,k) = T(n-1,k) + T^2(n-1,k-1) for k>0, where T^2 is the matrix square of T.at n=23A097712