2415
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 4608
- Proper Divisor Sum (Aliquot Sum)
- 2193
- 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
- 1056
- Möbius Function
- 1
- Radical
- 2415
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- yes
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- yes
- 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
- 120
- 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
- Hexagonal numbers: a(n) = n*(2*n-1).at n=35A000384
- Odd squarefree numbers with an even number of prime factors that have no prime factors greater than 31.at n=51A002557
- Number of spanning trees in P_4 X P_n.at n=2A003696
- Binomial coefficient C(5n, n-12).at n=2A004354
- Binomial coefficient C(7n,n-8).at n=2A004376
- Complexity of (or spanning trees in) a 3 X n grid.at n=3A006238
- Expansion of Jacobi theta constant theta_2^6 /(64q^(3/2)).at n=34A008440
- Expansion of (1+x^9)/((1-x)*(1-x^2)*(1-x^3)*(1-x^4)).at n=55A008770
- Expansion of e.g.f.: cos(log(1+x))/cos(x).at n=7A009025
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 3.at n=26A013591
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 4.at n=4A013592
- Odd triangular numbers.at n=34A014493
- a(n) = (2*n+1)*(4*n+1).at n=17A014634
- Binomial coefficients C(n,68).at n=2A017732
- Binomial coefficients C(70,n).at n=2A017786
- Smallest triangular number that begins with n.at n=23A018855
- a(n) = n*(11*n - 1)/2.at n=21A022268
- Expansion of Product_{m>=1} (1+m*q^m)^-20.at n=4A022712
- Place where n-th 1 occurs in A023125.at n=25A022787
- 2nd elementary symmetric function of the first n+1 positive integers congruent to 2 mod 3.at n=5A024391