216591216 has 20 divisors (see below), whose sum is σ = 559527432. Its totient is φ = 72197056.

The previous prime is 216591209. The next prime is 216591217. The reversal of 216591216 is 612195612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216591217) 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, 2256111 + ... + 2256206.

Almost surely, 2^216591216 is an apocalyptic number.

It is an amenable number.

216591216 is an abundant number, since it is smaller than the sum of its proper divisors (342936216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216591216 is a wasteful number, since it uses less digits than its factorization.

216591216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4512328 (or 4512322 counting only the distinct ones).

The product of its digits is 6480, while the sum is 33.

The square root of 216591216 is about 14717.0382890037. The cubic root of 216591216 is about 600.5469235285.

The spelling of 216591216 in words is "two hundred sixteen million, five hundred ninety-one thousand, two hundred sixteen".