17803
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18760
- Proper Divisor Sum (Aliquot Sum)
- 957
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16848
- Möbius Function
- 1
- Radical
- 17803
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 71
- 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
- Smallest number that requires n iterations of the bi-unitary totient function (A116550) to reach 1.at n=46A005424
- Numerator of [x^n] in the Taylor expansion of exp(cosech(x)-coth(x)).at n=10A013559
- Pseudoprimes to base 13.at n=42A020141
- Pseudoprimes to base 72.at n=39A020200
- Strong pseudoprimes to base 13.at n=8A020239
- Largest squarefree number k such that Q(sqrt(-k)) has class number n.at n=11A038552
- Convolutory inverse of signed lower Wythoff sequence.at n=17A078140
- a(0)=1, a(1)=4, a(n)=8a(n-1)-13a(n-2), n>=2.at n=6A083882
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 0), (1, 0, 0), (1, 0, 1), (1, 1, 0)}.at n=7A151163
- Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=5A252152
- Number of (n+2)X(6+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=2A252155
- T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=30A252157
- T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum not equal to 0 1 3 6 or 7 and every 3X3 diagonal and antidiagonal sum equal to 0 1 3 6 or 7.at n=33A252157
- Number of (n+2)X(7+2) 0..1 arrays with no 3x3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 2 and no column sum 2.at n=19A255227
- a(n) is the numerator of Sum_{d|n} sigma(n/d)^d/d, where sigma is A000203.at n=20A267310
- p-INVERT of (0,1,0,1,0,1,...), where p(S) = 1 - S - S^4.at n=16A291220
- a(n) = n*(n^3 + 2*n^2 - 5*n + 10)/8.at n=19A294259
- Numbers k such that there are exactly four biquadratefree powerful numbers (A338325) between k^2 and (k+1)^2.at n=15A338391
- Largest number k such that C(-k) is the cyclic group of order n, where C(D) is the class group of the quadratic field with discriminant D; or 0 if no such k exists.at n=11A357600