216782388 has 36 divisors (see below), whose sum is σ = 554587488. Its totient is φ = 71389200.

The previous prime is 216782347. The next prime is 216782389. The reversal of 216782388 is 883287612.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216782389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33288 + ... + 39263.

It is an arithmetic number, because the mean of its divisors is an integer number (15405208).

Almost surely, 2^216782388 is an apocalyptic number.

It is an amenable number.

216782388 is an abundant number, since it is smaller than the sum of its proper divisors (337805100).

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

216782388 is a wasteful number, since it uses less digits than its factorization.

216782388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72644 (or 72639 counting only the distinct ones).

The product of its digits is 258048, while the sum is 45.

The square root of 216782388 is about 14723.5317773963. The cubic root of 216782388 is about 600.7235604165.

The spelling of 216782388 in words is "two hundred sixteen million, seven hundred eighty-two thousand, three hundred eighty-eight".