216678400 has 135 divisors (see below), whose sum is σ = 561724681. Its totient is φ = 82903040.

The previous prime is 216678373. The next prime is 216678403. The reversal of 216678400 is 4876612.

The square root of 216678400 is 14720.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78004224 + 138674176 = 8832^2 + 11776^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216678403) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 9420789 + ... + 9420811.

Almost surely, 2^216678400 is an apocalyptic number.

216678400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

216678400 is the 14720-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216678400

216678400 is an abundant number, since it is smaller than the sum of its proper divisors (345046281).

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

216678400 is an frugal number, since it uses more digits than its factorization.

216678400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 34.

The cubic root of 216678400 is about 600.6274916764.

The spelling of 216678400 in words is "two hundred sixteen million, six hundred seventy-eight thousand, four hundred".