8245
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 19
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 10584
- Proper Divisor Sum (Aliquot Sum)
- 2339
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6144
- Möbius Function
- -1
- Radical
- 8245
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 127
- 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
- no
- Odd
- yes
Appears in sequences
- Powers of rooted tree enumerator.at n=16A000439
- a(n+6) = -a(n+5) + a(n+4) + 3a(n+3) + a(n+2) - a(n+1) - a(n). a(n) = sign(n) if abs(n)<=3.at n=32A001945
- Geometric mean of phi(n) and sigma(n) is an integer, n odd.at n=20A015705
- Pseudoprimes to base 98.at n=43A020226
- a(n+1) = [ A*a(n)+B ]/p^r, where p^r is the highest power of p diving [ A*a(n)+B ] and p=2, A=2.00013, B=3.0.at n=39A029580
- Row sums of triangle A049374.at n=5A049402
- Row sums of triangle A049424.at n=6A049427
- Permutation of N induced by rotating the node 4 left in the infinite planar binary tree shown at A065658.at n=32A065667
- Smallest term x from A066669 such that phi(x) = 2^n times some prime.at n=10A066673
- a(n) is the smallest number k such that A073813(k) = prime(n).at n=24A073814
- Number of asymmetric mobiles (cycle rooted trees) with n generators.at n=9A108529
- a(n) is such that the a(n)-th composite number is (n-th prime)^2.at n=24A120389
- Moessner triangle based on A000217.at n=16A125777
- (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, ...) becomes (0^1 + 2, 3^2 + 2, 5^2 + 3, 7^2 + 3, 3^2 + 2, 5^11 + 2, 2^3 + 13, ...).at n=34A143651
- Values of hypotenuse of primitive Pythagorean triples which can have four different shapes (that is, four different sets of "legs").at n=26A159781
- A determinant sequence of a matrix recursion: x(n)=x(n-1).(2*I-A.x(n-1)).at n=3A174320
- The number of multinomial coefficients, based on a set of partitions of n into m positions, divisible by m entirely.at n=31A200144
- Number of 2 X 2 matrices having all terms in {1,...,n} and determinant in the closed interval [0,n].at n=16A211057
- a(0)=0, a(1)=1; a(n)=a(n-1)+a(n-2) if a(n-1)+a(n-2) is not semiprime; otherwise a(n) is the largest prime divisor of a(n-1)+a(n-2).at n=36A214094
- Number of (n+2) X (2+2) 0..1 arrays with no 3 x 3 subblock diagonal sum 0 and no antidiagonal sum 0 and no row sum 2 and no column sum 2.at n=17A255222