216838457865 has 32 divisors (see below), whose sum is σ = 386746335360. Its totient is φ = 115270454592.

The previous prime is 216838457861. The next prime is 216838457867. The reversal of 216838457865 is 568754838612.

216838457865 is a `hidden beast` number, since 21 + 6 + 8 + 38 + 4 + 578 + 6 + 5 = 666.

It is not a de Polignac number, because 216838457865 - 2² = 216838457861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (216838457861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2574534 + ... + 2657423.

It is an arithmetic number, because the mean of its divisors is an integer number (12085822980).

Almost surely, 2^216838457865 is an apocalyptic number.

It is an amenable number.

216838457865 is a deficient number, since it is larger than the sum of its proper divisors (169907877495).

216838457865 is a wasteful number, since it uses less digits than its factorization.

216838457865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5232278 (or 5232272 counting only the distinct ones).

The product of its digits is 77414400, while the sum is 63.

The spelling of 216838457865 in words is "two hundred sixteen billion, eight hundred thirty-eight million, four hundred fifty-seven thousand, eight hundred sixty-five".