8318
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 12480
- Proper Divisor Sum (Aliquot Sum)
- 4162
- 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
- 4158
- Möbius Function
- 1
- Radical
- 8318
- 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
- 52
- 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
- yes
- Odd
- no
Appears in sequences
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t = A008578 ({1} U primes).at n=29A023862
- a(n) = 1*prime(n) + 2*prime(n-1) + ... + k*prime(n+1-k), where k=floor((n+1)/2) and prime(n) is the n-th prime.at n=28A023870
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 90.at n=15A031588
- Denominators of continued fraction convergents to sqrt(645).at n=7A042239
- Numbers beginning and ending with their multiplicative digital root.at n=45A064704
- Numbers k for which the sums of prime factors (ignoring multiplicity) of sigma(k) and phi(k) are equal but the sets of prime factors of sigma and phi are different.at n=28A081378
- Numbers m such that f(k) * 2^m - 1 is prime, where f(j) = A070826(j) and k is the number of decimal digits of 2^m.at n=34A095991
- (p*q - 1)/2 where p and q are consecutive odd primes.at n=29A102770
- a(n) consecutive digits descending beginning with the digit 4 give a prime.at n=7A120829
- Expansion of eta(q^3) * eta(q^33) / ( eta(q)* eta(q^11)) in powers of q.at n=41A128663
- a(n) = the n-th positive integer with exactly n zeros and n ones in its binary representation.at n=6A143960
- Number of 3-compositions of n.at n=6A145839
- A functionally symmetric Polynomial as a triangle of coefficients: p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 3)*Sum[(3^(m-1) + 2*m+1 )*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].at n=49A146958
- A functionally symmetric Polynomial as a triangle of coefficients: p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n - 3)*Sum[(3^(m-1) + 2*m+1 )*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].at n=50A146958
- Number of partitions of n into as many primes as nonprimes.at n=47A155515
- 1/8 the number of n X n arrays of squares of integers with every 2X2 subblock summing to 31.at n=12A159230
- Sums of two (not necessarily distinct) Mersenne primes (A000668).at n=13A171251
- Number of skew partitions of n whose diagrams have no empty rows and columns.at n=9A225114
- Minimal index of order n Stanley's antimagic square composed of Smith numbers.at n=4A225133
- Minimum value unattainable as the sum of 2 attained values of a*b+a*c+b*c with a,b,c 0..n integers.at n=39A225272