216515912 has 8 divisors (see below), whose sum is σ = 405967350. Its totient is φ = 108257952.

The previous prime is 216515909. The next prime is 216515917. The reversal of 216515912 is 219515612.

216515912 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 only one way, i.e., 198077476 + 18438436 = 14074^2 + 4294^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (216515917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13532237 + ... + 13532252.

Almost surely, 2^216515912 is an apocalyptic number.

It is an amenable number.

216515912 is a deficient number, since it is larger than the sum of its proper divisors (189451438).

216515912 is a wasteful number, since it uses less digits than its factorization.

216515912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27064495 (or 27064491 counting only the distinct ones).

The product of its digits is 5400, while the sum is 32.

The square root of 216515912 is about 14714.4796713985. The cubic root of 216515912 is about 600.4773164772.

The spelling of 216515912 in words is "two hundred sixteen million, five hundred fifteen thousand, nine hundred twelve".