216400800 has 288 divisors, whose sum is σ = 878943744. Its totient is φ = 44928000.

The previous prime is 216400781. The next prime is 216400867. The reversal of 216400800 is 8004612.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 184215 + ... + 185385.

It is an arithmetic number, because the mean of its divisors is an integer number (3051888).

Almost surely, 2^216400800 is an apocalyptic number.

216400800 is a gapful number since it is divisible by the number (20) 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 216400800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (439471872).

216400800 is an abundant number, since it is smaller than the sum of its proper divisors (662542944).

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

216400800 is a wasteful number, since it uses less digits than its factorization.

216400800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1212 (or 1199 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 216400800 is about 14710.5676301086. The cubic root of 216400800 is about 600.3708818083.

The spelling of 216400800 in words is "two hundred sixteen million, four hundred thousand, eight hundred".