15994
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 26208
- Proper Divisor Sum (Aliquot Sum)
- 10214
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7260
- Möbius Function
- -1
- Radical
- 15994
- 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
- 53
- 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
- Number of Hamiltonian cycles in D_4 X P_n.at n=8A003759
- Expansion of ( Sum_{n = -infinity..infinity} x^(n^2) )^(-11).at n=4A004412
- a(n)=phi(n^2+1)/n if (n^2+1) is composite and phi(n^2+1)==0 (mod n).at n=30A067926
- Numbers n for which there are exactly five k such that n = k + reverse(k).at n=37A072429
- G.f. A(x) satisfies xA(x)^5 = B(xA(x^5)) where B(x) = x/(1-5x).at n=8A091200
- Sum of smallest parts (counted with multiplicity) of all compositions of n.at n=12A097940
- Half-sum (or average) of cubes of two distinct odd primes.at n=39A138855
- a(n) = 2662*n + 22.at n=5A157613
- G.f.: 1 / Product_{i>=1} (1-q^(2*i-1))^2*(1-q^(12*i-8))*(1-q^(12*i-6))*(1-q^(12*i-4))*(1-q^(12*i)).at n=26A201077
- Triangle read by rows, T(n,k) = !n + (k-1)*(n-1)!, with n>=1, 1<=k<=n; Position of the first n-letter permutation beginning with number k in the list of lexicographically sorted permutations A030299.at n=30A237450
- Numbers k such that (29*10^k + 91)/3 is prime.at n=31A269797
- a(n) = Sum_{i=1..floor((n-1)/2)} i * (n-i)^2.at n=22A308038
- Number of integers in base n having exactly four distinct digits such that the number formed by the consecutive subsequence of the initial j digits is divisible by j for all j in {1,2,3,4}.at n=27A333469