1509
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2016
- Proper Divisor Sum (Aliquot Sum)
- 507
- 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
- 1004
- Möbius Function
- 1
- Radical
- 1509
- 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
- 65
- 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
- Expansion of 1/(1-x)^2/(1-x^2)/(1-x^4)/(1-x^10)/(1-x^20).at n=32A001307
- Sequence and first differences (A030124) together list all positive numbers exactly once.at n=49A005228
- Discriminants of totally real cubic fields.at n=44A006832
- Coordination sequence T4 for Zeolite Code MEL.at n=25A008153
- Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite DDR = Deca-dodecasil 3R[Si120O240]qR starting with a T7 atom.at n=10A019109
- Expansion of Product_{m>=1} (1+x^m)^12.at n=4A022577
- Place where n-th 1 occurs in A023117.at n=36A022779
- a(n) = a(n-1) + c(n-1) for n >= 2, a( ) increasing, given a(1)=3, where c( ) is complement of a( ).at n=49A022935
- a(n) = a(n-1) + c(n+1) for n >= 3, a( ) increasing, given a(1)=1, a(2)=7; where c( ) is complement of a( ).at n=48A022953
- Number of up/down (initially ascending) compositions of n.at n=18A025048
- Numbers that are the sum of 3 nonzero squares in exactly 10 ways.at n=30A025330
- Numbers that are the sum of 3 distinct nonzero squares in exactly 10 ways.at n=30A025348
- Index of 4^n within the sequence of the numbers of the form 3^i*4^j.at n=48A025701
- Triangle T read by rows: differences of Motzkin triangle (A026300).at n=61A026105
- a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is a nonnegative integer, s(0) = 0, s(1) = 1, s(n) = 4, |s(i) - s(i-1)| <= 1 for i >= 2. Also a(n) = T(n,n-4), where T is the array defined in A026105.at n=6A026110
- T(2n,n+1), where T is the array defined in A026105.at n=4A026116
- Number of partitions of n into an odd number of parts, the greatest being 6; also, a(n+11) = number of partitions of n+5 into an even number of parts, each <=6.at n=43A026926
- Golc sequence in base 2. Left to right concatenation of n,int(log_2(n)),int(log_2(int(log_2(n)))),... in base 2.at n=22A028432
- Q(sqrt(n)) has class number 3.at n=28A029703
- Positions of records in A030757.at n=35A030762