216645818 has 8 divisors (see below), whose sum is σ = 325061748. Its totient is φ = 108291904.

The previous prime is 216645811. The next prime is 216645827. The reversal of 216645818 is 818546612.

216645818 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 214534609 + 2111209 = 14647^2 + 1453^2 .

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

It is not an unprimeable number, because it can be changed into a prime (216645811) 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, 5471 + ... + 21522.

Almost surely, 2^216645818 is an apocalyptic number.

216645818 is a deficient number, since it is larger than the sum of its proper divisors (108415930).

216645818 is a wasteful number, since it uses less digits than its factorization.

216645818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31008.

The product of its digits is 92160, while the sum is 41.

The square root of 216645818 is about 14718.8932328487. The cubic root of 216645818 is about 600.5973846515.

The spelling of 216645818 in words is "two hundred sixteen million, six hundred forty-five thousand, eight hundred eighteen".