216864864 has 108 divisors (see below), whose sum is σ = 643403124. Its totient is φ = 71855424.

The previous prime is 216864859. The next prime is 216864887. The reversal of 216864864 is 468468612.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

216864864 is a `hidden beast` number, since 2 + 168 + 6 + 486 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (108).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1298509 + ... + 1298675.

Almost surely, 2^216864864 is an apocalyptic number.

216864864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216864864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321701562).

216864864 is an abundant number, since it is smaller than the sum of its proper divisors (426538260).

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

216864864 is an frugal number, since it uses more digits than its factorization.

216864864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 172 counting only the distinct ones).

The product of its digits is 442368, while the sum is 45.

The square root of 216864864 is about 14726.3323336125. The cubic root of 216864864 is about 600.7997335701.

The spelling of 216864864 in words is "two hundred sixteen million, eight hundred sixty-four thousand, eight hundred sixty-four".