216389888 has 144 divisors (see below), whose sum is σ = 531570816. Its totient is φ = 86507520.

The previous prime is 216389867. The next prime is 216389897. The reversal of 216389888 is 888983612.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 841856 + ... + 842112.

It is an arithmetic number, because the mean of its divisors is an integer number (3691464).

Almost surely, 2^216389888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216389888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265785408).

216389888 is an abundant number, since it is smaller than the sum of its proper divisors (315180928).

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

216389888 is a wasteful number, since it uses less digits than its factorization.

216389888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320 (or 306 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 53.

The square root of 216389888 is about 14710.1967355981. The cubic root of 216389888 is about 600.3607904144.

The spelling of 216389888 in words is "two hundred sixteen million, three hundred eighty-nine thousand, eight hundred eighty-eight".