16643 has 8 divisors (see below), whose sum is σ = 19440. Its totient is φ = 14080.

The previous prime is 16633. The next prime is 16649. The reversal of 16643 is 34661.

16643 is nontrivially palindromic in base 9.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16643 - 2¹⁰ = 15619 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (16649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143 + ... + 231.

It is an arithmetic number, because the mean of its divisors is an integer number (2430).

2¹⁶⁶⁴³ is an apocalyptic number.

16643 is a deficient number, since it is larger than the sum of its proper divisors (2797).

16643 is a wasteful number, since it uses less digits than its factorization.

16643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117.

The product of its digits is 432, while the sum is 20.

The square root of 16643 is about 129.0077517051. The cubic root of 16643 is about 25.5315513591.

The spelling of 16643 in words is "sixteen thousand, six hundred forty-three".