216868864 has 48 divisors (see below), whose sum is σ = 459213300. Its totient is φ = 102039552.

The previous prime is 216868811. The next prime is 216868867. The reversal of 216868864 is 468868612.

It can be written as a sum of positive squares in 2 ways, for example, as 211993600 + 4875264 = 14560^2 + 2208^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (216868867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31702 + ... + 37930.

Almost surely, 2^216868864 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 216868864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229606650).

216868864 is an abundant number, since it is smaller than the sum of its proper divisors (242344436).

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

216868864 is an equidigital number, since it uses as much as digits as its factorization.

216868864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6268 (or 6248 counting only the distinct ones).

The product of its digits is 884736, while the sum is 49.

The square root of 216868864 is about 14726.4681441274. The cubic root of 216868864 is about 600.8034273975.

The spelling of 216868864 in words is "two hundred sixteen million, eight hundred sixty-eight thousand, eight hundred sixty-four".