8145
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
- 12
- Divisor Sum
- 14196
- Proper Divisor Sum (Aliquot Sum)
- 6051
- 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
- 4320
- Möbius Function
- 0
- Radical
- 2715
- Omega Function (Ω)
- 4
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 158
- Smith Number
- no
- 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
- no
- Odd
- yes
Appears in sequences
- Let F(x) = 1 + x + 4x^2 + 10x^3 + ... = g.f. for A000293 (solid partitions) and expand (1-x)(1-x^2)(1-x^3)...*F(x) in powers of x.at n=13A002836
- a(n) = n*(4*n+1).at n=45A007742
- Nearest integer to (n/2)^4.at n=19A011863
- Pseudoprimes to base 19.at n=36A020147
- Number of compositions into sums of cubes.at n=47A023358
- Odd numbers with exactly 4 palindromic prime factors (counted with multiplicity).at n=43A046374
- Number of 3 X 3 integer matrices with elements in the range [ -n,n ] which represent a rotation of order 2.at n=7A053171
- Numbers n such that n | 12^n + 11^n + 10^n + 9^n + 8^n + 7^n + 6^n + 5^n + 4^n + 3^n.at n=37A057289
- Sum of the quadratic residues of prime(n).at n=41A076409
- Least nontrivial multiple of the n-th prime beginning with 8.at n=41A078292
- Numbers n such that h(n) = 3 h(n-1) where h(n) is the length of the sequence {n, f(n), f(f(n)), ...., 1} in the Collatz (or 3x + 1) problem. (The earliest "1" is meant.)at n=7A078420
- Numbers k such that p(k), p(k)+6, p(k)+12, p(k)+18 are consecutive primes, where p(k) denotes k-th prime.at n=29A090832
- Numbers n such that p(n),p(n)+6,p(n)+12,p(n)+18 are consecutive primes and p(n)=6*k+1 for some k, where p(n) denotes n-th prime.at n=14A090838
- Partial sums of A000960.at n=30A099074
- a(n) = J_4(n)/240.at n=32A115002
- Sum of the quadratic nonresidues of prime(n).at n=41A125615
- n^4 - 1 divided by its largest fourth power divisor.at n=17A128251
- Sum of even products minus sum of odd products of different pairs of numbers from 1 to n.at n=18A134449
- a(n) = 4*n^2 + 73*n + 333.at n=35A157431
- Numerator of Euler(n, 1/32).at n=3A157767