17220
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
- 48
- Divisor Sum
- 56448
- Proper Divisor Sum (Aliquot Sum)
- 39228
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3840
- Möbius Function
- 0
- Radical
- 8610
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 5
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 79
- 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
- yes
- Odd
- no
Appears in sequences
- G.f.: 2*(1-x^3)/((1-x)^5*(1+x)^2).at n=39A005996
- a(n) = floor(n*(n-1)*(n-2)/4).at n=42A011886
- Perimeters of more than one primitive Pythagorean triangle.at n=28A024408
- Numbers whose set of base-16 digits is {3,4}.at n=25A032840
- Triangle read by rows: T(n,k) = number of labeled digraphs with n nodes and k arcs and without directed paths of length >=2, with 0 <= k <= floor(n^2/4).at n=33A052296
- Consider all integer triples (i,j,k), j >= k > 0, with binomial(i+2,3)=j^3+k^3, ordered by increasing i; sequence gives k values.at n=29A054207
- Smallest area of a Pythagorean triangle with n as length of a leg.at n=38A054436
- Triangle read by rows: T(n,k) = number of noncommutative symmetric polynomials of degree n that have exactly k different variables appearing in each monomial and which generate the algebra of all noncommutative symmetric polynomials (n >= 1, 1 <= k <= n).at n=50A055105
- Triangle T(n,k) giving number of symmetric polynomials of degree n in k noncommuting variables, n >=2, 2 <= k <= n.at n=40A055106
- Triangle T(k,n) giving number of symmetric polynomials of degree n in k noncommuting variables, n >=2, 2 <= k <= n.at n=40A055107
- a(n) = n*(n+1)*(2*n+1).at n=20A055112
- Largest area of a Pythagorean triangle with n as length of one of the three sides (in fact as a leg).at n=38A055522
- Number of prime triples < 10^n, where a prime triple means 3 successive primes of the form {p, p+2, p+4} or {p, p+4, p+6}.at n=6A055737
- Numbers k such that 2^k + 3 is prime.at n=32A057732
- Triangular array T(n,k) giving number of alternating link diagrams with n >= 0 crossings, k = 0..[n/2] connected components and two external legs.at n=18A062038
- Value of remainder r (see A065052) at start of n-th interval between special points in Recamán's sequence A005132.at n=16A065054
- Number of alternating link diagrams with n crossings, 2 connected components and two external legs.at n=3A067767
- Numbers k such that the sign of core(k)-phi(k) is not equal to 2*mu(k)^2-1, where core(k) is the squarefree part of k.at n=28A070237
- Least number beginning with n such that every partial sum is a square.at n=16A095158
- Indices of primes in sequence defined by A(0) = 47, A(n) = 10*A(n-1) - 53 for n > 0.at n=10A101717