8154
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 18240
- Proper Divisor Sum (Aliquot Sum)
- 10086
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 2700
- Möbius Function
- 0
- Radical
- 906
- Omega Function (Ω)
- 5
- 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
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 65
- Smith Number
- yes
- 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
- Let A(n) = #{(i,j,k): i^2 + j^2 + k^2 <= n}, V(n) = (4/3)Pi*n^(3/2), P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=38A000092
- Numbers k where |cos(k)| (or |cosec(k)| or |cot(k)|) decreases monotonically to 0; also numbers k where |tan(k)| (or |sec(k)|, or |sin(k)|) increases.at n=28A004112
- Number of Barlow packings with group P3m1 that repeat after n layers.at n=12A011953
- Number of permutations of {1,2,...,n} in which each element follows its proper divisors.at n=10A016021
- (s(n)+s(n+1))/6, where s()=A006521.at n=16A016059
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = A001950 (upper Wythoff sequence).at n=21A024465
- Least k such that tan(k) > tan(a(n-1)), for n >= 1, where a(0) = 0.at n=39A024814
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Fibonacci numbers), t = A001950 (upper Wythoff sequence).at n=21A025085
- Number of partitions of n with equal nonzero number of parts congruent to each of 0 and 2 (mod 5).at n=44A035563
- Sin(n) decreases monotonically to -1.at n=16A046964
- a(n)/n^2 is the minimal average squared Euclidean distance of n points to their center of gravity among all configurations of n points on the hexagonal lattice.at n=38A059518
- Length of period of the continued fraction expansion of sqrt(2^n+1).at n=29A059926
- Length of period of continued fraction expansion of square root of (2^(2n+1)+1).at n=14A061682
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 95 ).at n=25A063368
- Numbers k such that floor(tan(k)) > floor(tan(m)) for all m < k.at n=36A063537
- Sum of terms of n-th group in A075383.at n=17A075386
- a(0)=1; a(n) is the smallest integer > a(n-1) such that sin(a(n)) is closer to an integer (here 0 or -1) than sin(a(n-1)).at n=15A079037
- Leading diagonal of A083173.at n=35A083174
- First differences are formed by interleaving {2^k - 1, k = 1, 2, 3, ...} and {11*k, k = 5, 4, 3, ...}.at n=24A086848
- Expansion of g.f. Product((1+x^i)/(1-x^i),i=1..n-1)/(1-x^n), with n = 6.at n=26A091774