1239
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
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 1920
- Proper Divisor Sum (Aliquot Sum)
- 681
- 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
- 696
- Möbius Function
- -1
- Radical
- 1239
- 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
- 132
- 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
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^3)).at n=32A000601
- Number of non-stereoisomeric paraffins with n carbon atoms.at n=16A000627
- Number of subwords of length n in infinite word generated by a -> aab, b -> b.at n=53A006697
- Number of nonsplit type 2 metacyclic 2-groups of order 2^n.at n=46A007981
- Coordination sequence T2 for Zeolite Code BPH.at n=27A008056
- Coordination sequence T1 for Zeolite Code LAU.at n=25A008124
- Expansion of exp(tan(x))*x.at n=7A009243
- Coordination sequence T1 for Zeolite Code -CLO.at n=31A009850
- Coordination sequence T4 for Zeolite Code RSN.at n=23A009888
- Crystal ball sequence for squashed {D_5}^* lattice, perhaps the smallest example of a "non-superficial" lattice.at n=4A010025
- Numbers n such that phi(n) * sigma(n) + 16 is a perfect square.at n=30A015729
- Place where n-th 1 occurs in A007336.at n=41A022775
- a(n) = a(n-1) + c(n-1) for n >= 2, a( ) increasing, given a(1)=4; where c( ) is complement of a( ).at n=44A022936
- Convolution of odd numbers and A000201.at n=12A023658
- Numbers with exactly 3 4's in base 5 expansion.at n=26A023740
- Index of 6^n within the sequence of the numbers of the form 6^i*9^j.at n=54A025718
- Coordination sequence T3 for Zeolite Code CGS.at n=26A027367
- For n odd, >1, not divisible by 3, we can write 3/n = 1/a + 1/b + 1/c with a>b>c>0, a,b,c distinct and odd; sequence gives smallest a.at n=18A027442
- For n != 1 mod 3, we can write 3/(2n+1) = 1/a + 1/b + 1/c with a>b>c>0, a,b,c distinct and odd; sequence gives smallest such a, or 1 if n = 1 mod 3.at n=28A027443
- Numbers k such that k divides the (right) concatenation of all numbers <= k written in base 4 (most significant digit on right).at n=5A029497