216673 has 4 divisors (see below), whose sum is σ = 217620. Its totient is φ = 215728.

The previous prime is 216661. The next prime is 216679. The reversal of 216673 is 376612.

216673 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 33489 + 183184 = 183^2 + 428^2 .

It is a cyclic number.

It is not a de Polignac number, because 216673 - 2⁵ = 216641 is a prime.

It is a Duffinian number.

216673 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (216679) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111 + ... + 667.

It is an arithmetic number, because the mean of its divisors is an integer number (54405).

2²¹⁶⁶⁷³ is an apocalyptic number.

It is an amenable number.

216673 is a deficient number, since it is larger than the sum of its proper divisors (947).

216673 is an equidigital number, since it uses as much as digits as its factorization.

216673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 946.

The product of its digits is 1512, while the sum is 25.

The square root of 216673 is about 465.4814711672. The cubic root of 216673 is about 60.0622502077.

The spelling of 216673 in words is "two hundred sixteen thousand, six hundred seventy-three".