216678823 has 4 divisors (see below), whose sum is σ = 216961360. Its totient is φ = 216396288.

The previous prime is 216678799. The next prime is 216678827. The reversal of 216678823 is 328876612.

216678823 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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216678823 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216678823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216678827) 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, 140115 + ... + 141652.

It is an arithmetic number, because the mean of its divisors is an integer number (54240340).

Almost surely, 2^216678823 is an apocalyptic number.

216678823 is a deficient number, since it is larger than the sum of its proper divisors (282537).

216678823 is an equidigital number, since it uses as much as digits as its factorization.

216678823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282536.

The product of its digits is 193536, while the sum is 43.

The square root of 216678823 is about 14720.0143681995. The cubic root of 216678823 is about 600.6278825248.

The spelling of 216678823 in words is "two hundred sixteen million, six hundred seventy-eight thousand, eight hundred twenty-three".