216811378 has 12 divisors (see below), whose sum is σ = 378313902. Its totient is φ = 92919120.

The previous prime is 216811369. The next prime is 216811391. The reversal of 216811378 is 873118612.

It can be written as a sum of positive squares in only one way, i.e., 214241769 + 2569609 = 14637^2 + 1603^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1106083 + ... + 1106278.

Almost surely, 2^216811378 is an apocalyptic number.

216811378 is a deficient number, since it is larger than the sum of its proper divisors (161502524).

216811378 is a wasteful number, since it uses less digits than its factorization.

216811378 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2212377 (or 2212370 counting only the distinct ones).

The product of its digits is 16128, while the sum is 37.

The square root of 216811378 is about 14724.5162229528. The cubic root of 216811378 is about 600.7503371916.

The spelling of 216811378 in words is "two hundred sixteen million, eight hundred eleven thousand, three hundred seventy-eight".