2905
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4032
- Proper Divisor Sum (Aliquot Sum)
- 1127
- 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
- 1968
- Möbius Function
- -1
- Radical
- 2905
- Omega Function (Ω)
- 3
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 48
- 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
- no
- Odd
- yes
Appears in sequences
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); A000092 gives values of n where |P(n)| sets a new record; sequence gives (nearest integer to, I believe) P(A000092(n)).at n=48A000223
- MacMahon's solid partitions of n in which 4 is the smallest summand.at n=10A002045
- Coordination sequence T1 for Zeolite Code PHI.at n=39A008227
- Expansion of e.g.f. tan(tanh(x))*exp(x).at n=9A009716
- Expansion of tanh(tan(x))*cos(x).at n=4A009809
- Coordination sequence T5 for Zeolite Code DFO.at n=41A009879
- Number of ordered triples of integers from [ 1,n ] with no common factors between pairs.at n=38A015632
- Pseudoprimes to base 82.at n=40A020210
- Numbers k such that the continued fraction for sqrt(k) has period 34.at n=30A020373
- a(n) = a(n-1) + a(n-2) + 1, with a(0)=3, a(1)=9.at n=13A022408
- Lucky numbers with size of gaps equal to 8 (lower terms).at n=33A031890
- Number of ordered rooted trees with n non-root nodes and all outdegrees <= three.at n=9A036765
- Coordination sequence T5 for Zeolite Code STT.at n=36A038415
- Number of partitions satisfying cn(0,5) + cn(2,5) <= 1 and cn(0,5) + cn(3,5) <= 1.at n=39A039851
- The sequence e when b=[ 1,1,1,0,1,1,... ].at n=48A042957
- Numbers k such that the string 7,7 occurs in the base 9 representation of k but not of k-1.at n=35A044321
- Numbers n such that string 0,5 occurs in the base 10 representation of n but not of n-1.at n=30A044337
- Numbers n such that string 7,7 occurs in the base 9 representation of n but not of n+1.at n=35A044702
- Numbers n such that string 0,5 occurs in the base 10 representation of n but not of n+1.at n=30A044718
- Numbers which, when expressed as a sum of distinct primes with maximum product, use a non-maximal number of primes.at n=14A053020