6615
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
- 24
- Divisor Sum
- 13680
- Proper Divisor Sum (Aliquot Sum)
- 7065
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3024
- Möbius Function
- 0
- Radical
- 105
- Omega Function (Ω)
- 6
- 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
- 75
- 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
- Number of stable feedback shift registers with n stages.at n=3A001139
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals rooted at a cell up to rotation and reflection.at n=34A003452
- Odd abundant numbers (odd numbers m whose sum of divisors exceeds 2m).at n=11A005231
- Molien series for A_9.at n=35A008632
- Number of partitions of n into at most 9 parts.at n=35A008638
- Expansion of 1/((1-x)*(1-2*x)*(1-3*x)*(1-7*x)).at n=4A021034
- a(n) = d(n)/2, where d = A026040.at n=31A026041
- Number of partitions of n in which the greatest part is 9.at n=44A026815
- Expansion of 1/((1-4x)(1-5x)(1-8x)(1-10x)).at n=3A028121
- Numbers having three 0's in base 9.at n=21A043455
- Odd numbers divisible by exactly 6 primes (counted with multiplicity).at n=17A046319
- Numbers that divide the sum of cubes of their divisors.at n=27A046763
- Number of 3 X n nonnegative integer matrices with all column sums 4, up to row and column permutation.at n=6A058408
- Polynomial extrapolation of 2, 3, 5, 7, 11.at n=17A061165
- Positive numbers whose product of digits is 10 times their sum.at n=37A062043
- a(n) = 15*n^2.at n=21A064761
- Numbers k such that sigma_k(k)/k is an integer, where sigma_k(k) is the sum of the k-th powers of the divisors of k (A023887).at n=45A067313
- a(n) = 3*n^2 + 12*n.at n=44A067707
- a(n) = A061680(n!).at n=44A069785
- Numbers k such that sigma(core(k)) = tau(k) where core(k) is the squarefree part of k, tau(k) is the number of divisors of k, and sigma(k) is their sum.at n=39A069827