17149
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 18720
- Proper Divisor Sum (Aliquot Sum)
- 1571
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15580
- Möbius Function
- 1
- Radical
- 17149
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 128
- Smith Number
- yes
- 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
- a(n) = a(n-1) + a(n-9) for n >= 9; a(n) = 1 for n=0..7; a(8) = 2.at n=54A005711
- Number of leftist trees with n leaves.at n=15A006196
- Integer part of square root of the reciprocal of a number multiplied by 10 to the power of the integer part of the square root of the number.at n=33A089245
- Series reversion of g.f. A(x) is -A(-x).at n=14A089796
- Female of (1/(n+1),n/(1+n)) pair function used to get a dual population Fibonacci.at n=23A100582
- Number of bi-secondary structures of size N.at n=11A119495
- Least k such that n^k mod k = n-1.at n=12A128149
- a(n) = least k such that the remainder when 15^k is divided by k is n.at n=13A128155
- a(n) = 14*n^2 - 1.at n=34A158485
- a(n) is the least integer k such that there are n values of i <= k for which gpf(i^2 + 1) = gpf(k^2 + 1), where gpf(x) is the greatest prime factor of x.at n=25A258840
- Number of nX3 0..1 arrays with every element equal to 0, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero.at n=19A298662
- Numbers k such that k and k+1 are both hoax numbers (A019506).at n=30A329935
- Numbers k such that A361338(k) = 9.at n=31A361348
- a(n) = Sum_{1 <= x_1, x_2, x_3 <= n} gcd(x_1, x_2, x_3, n)^5.at n=6A372930