16018
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 24030
- Proper Divisor Sum (Aliquot Sum)
- 8012
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8008
- Möbius Function
- 1
- Radical
- 16018
- 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
- 45
- 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
- Numbers whose base-5 representation contains exactly three 0's and three 3's.at n=11A045202
- a(n) is twice the smallest k such that A051686(k) = prime(n).at n=46A051692
- Twice the positions in A051686 at which new primes appear in that sequence.at n=43A051861
- Numbers k such that 3^k + phi(k) is prime.at n=11A109887
- Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1111-1111 pattern in any orientation.at n=16A146939
- T(n,m) = number of 1..m integer arrays v[1..n] of length n with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..n-1.at n=59A171275
- Number of 1..7 integer arrays v[1..n] of length n with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..n-1.at n=4A171281
- Number of 1..n integer arrays v[1..5] of length 5 with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..4.at n=6A171342
- Main diagonal of square arrays A114881 and A249741.at n=22A249743
- G.f.: Sum_{n=-oo..+oo} x^n * (1 + x^n)^n, an even function.at n=56A260361
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 233", based on the 5-celled von Neumann neighborhood.at n=28A270978
- a(n) = 32*n^2 - 40*n + 10.at n=22A343578
- The number of six-term Egyptian fractions of rational numbers, x/y, 0 < x/y < 1, ordered as below. The sequence is the number of (p,q,r,s,t,u) such that x/y = 1/p + 1/q + 1/r + 1/s + 1/t + 1/u where p, q, r, s, t, and u are integers with p < q < r < s < t < u.at n=14A349086
- Number of mutual-visibility sets in the n-web graph.at n=4A389188