15042
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 12
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 31680
- Proper Divisor Sum (Aliquot Sum)
- 16638
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4752
- Möbius Function
- 1
- Radical
- 15042
- 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
- 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
- 45
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = floor( n*(n-1)*(n-2)*(n-3)/28 ).at n=27A011938
- Powers of fourth root of 13 rounded up.at n=15A018083
- Number of partitions satisfying cn(2,5) <= 1 and cn(3,5) <= 1.at n=44A039855
- Dana Scott's sequence: a(n) = (a(n-2) + a(n-1) * a(n-3)) / a(n-4), a(0) = a(1) = a(2) = a(3) = 1.at n=17A048736
- Indices of prime generalized tetranacci numbers, A073817.at n=26A104577
- Numbers k such that the centered triangular number A005448(k) = 3*k*(k-1)/2 + 1 is a perfect square.at n=10A129444
- Number of permutations of 4 indistinguishable copies of 1..n arranged in a circle with exactly 4 local maxima.at n=2A159730
- Number of strictly increasing arrangements of 4 numbers in -(n+2)..(n+2) with sum zero.at n=38A188182
- Number of (w,x,y,z) with all terms in {1,...,n} and 2*w*x>=3*y*z.at n=14A211923
- Positive even numbers which are neither of the form p + 2^m + 1 nor of the form p + 2^m - 1 with p prime.at n=21A270446
- Number of binary palindromes of length 2n+1 having no (7/3)+ powers.at n=49A279611
- a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = 1, a(1) = 3, a(2) = 4, a(3) = 5.at n=23A295718
- Setwise difference A340150 \ A340076.at n=34A340151
- Products k of 4 distinct primes (or tetraprimes) such that k has no squarefree neighbors.at n=14A364141
- Products k of 4 distinct primes (or tetraprimes) such that none of k-2, k-1, k+1 and k+2 is squarefree.at n=6A364766
- Indices of the Sylvester primes (A375543) in the primes (A000040).at n=27A375545
- a(n) is the largest number t such that there exist numbers i,j,k such that, for all m <= t, there exist integers x,y,z with x*i + y*j + z*k = m and |x|+|y|+|z| <= n.at n=33A383579