16145
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19380
- Proper Divisor Sum (Aliquot Sum)
- 3235
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12912
- Möbius Function
- 1
- Radical
- 16145
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 71
- 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
- no
- Odd
- yes
Appears in sequences
- Schoenheim bound L_1(n,n-5,n-6).at n=20A036837
- Gives an LCD representation of n.at n=16A071843
- a(n) = smallest composite (odd) number greater than a(n-1) such that a(n)+2n is the first prime after a(n).at n=18A189118
- Number of distinct sums of subsets of the first n squares {1,4,9,...,n^2}.at n=35A208531
- a(n) = (binomial(n,5) - floor(n/5)) / 5.at n=21A215052
- Number of distinct row and column sums for n X n (0, 1)-matrices.at n=4A297077
- Array read by antidiagonals: T(n,m) is the number of acyclic edge sets in the complete bipartite graph K_{n,m}.at n=40A328887
- a(n) = Sum_{k>=0} (n*k - 1)^n / 2^(k + 1).at n=4A330604
- a(n) = Sum_{k=1..n} gcd(k, n)^3.at n=24A343497
- Number of compositions (ordered partitions) of n into at most 5 prime powers (including 1).at n=39A347775
- Semiprimes p*q such that p*q+p+q, p*q-(p+q), p*q+2*(p+q) and p*q-2*(p+q) are all primes.at n=22A356765
- Number of compositions of 2n into n parts where differences between neighboring parts are in {-1,1}.at n=29A364529
- Expansion of e.g.f. exp(-x) / (2 - exp(4*x)).at n=4A367981