216388756 has 6 divisors (see below), whose sum is σ = 378680330. Its totient is φ = 108194376.

The previous prime is 216388727. The next prime is 216388787. The reversal of 216388756 is 657883612.

216388756 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., 144817156 + 71571600 = 12034^2 + 8460^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27048591 + ... + 27048598.

Almost surely, 2^216388756 is an apocalyptic number.

It is an amenable number.

216388756 is a deficient number, since it is larger than the sum of its proper divisors (162291574).

216388756 is a wasteful number, since it uses less digits than its factorization.

216388756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54097193 (or 54097191 counting only the distinct ones).

The product of its digits is 483840, while the sum is 46.

The square root of 216388756 is about 14710.1582588360. The cubic root of 216388756 is about 600.3597435238.

The spelling of 216388756 in words is "two hundred sixteen million, three hundred eighty-eight thousand, seven hundred fifty-six".