3115
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4320
- Proper Divisor Sum (Aliquot Sum)
- 1205
- 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
- 2112
- Möbius Function
- -1
- Radical
- 3115
- 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
- 61
- 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
- Describe the previous term! (method A - initial term is 5).at n=3A001141
- Numbers k such that 9*2^k - 1 is prime.at n=20A002236
- a(n) = C(n+2,3) + C(n,3) + C(n-1,3).at n=18A006004
- Numbers n such that phi(n + 1) | sigma(n) for n congruent to 1 (mod 3).at n=16A015817
- (d(n)-r(n))/5, where d = A006527 and r is the periodic sequence with fundamental period (4,1,4,0,1).at n=34A026036
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 11.at n=27A031509
- Coordination sequence T4 for Zeolite Code SBE.at n=45A033607
- Numbers n such that string 1,5 occurs in the base 10 representation of n but not of n-1.at n=34A044347
- Numbers n such that string 1,5 occurs in the base 10 representation of n but not of n+1.at n=34A044728
- Composite numbers k such that sigma(k + 6!) = sigma(k + 720) = sigma(k) + 720.at n=26A054984
- Multiples of 7 containing only odd digits.at n=40A061825
- Number of isomorphism classes of non-associative non-commutative closed binary operations on a set of order n, listed by class size.at n=7A079194
- a(n) = n^n - n(n-1)/2.at n=4A080523
- Expansion of e.g.f. exp(x) * (sec(exp(x) - 1))^2.at n=6A080832
- Multiples of 5 in which there is no common digit in successive terms.at n=18A083493
- Multiples of 7 in which there is no common digit in successive terms.at n=17A083495
- Numbers k such that A083539(k) is a square; solutions x to sigma(x+1)*sigma(x)=y^2 for some y.at n=28A083540
- a(n) = A069837(n) - (10^n-1)*2/9.at n=31A098831
- Number of different cuboids with volume (pq)^n, where p,q are distinct prime numbers.at n=15A101427
- Expansion of 1 / ((1-x-x^2-x^3)*(1-x^2-x^3)).at n=13A103322