216686400 has 168 divisors, whose sum is σ = 812596800. Its totient is φ = 49520640.

The previous prime is 216686399. The next prime is 216686413. The reversal of 216686400 is 4686612.

It is a happy number.

216686400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (168).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30376 + ... + 36824.

Almost surely, 2^216686400 is an apocalyptic number.

216686400 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 216686400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (406298400).

216686400 is an abundant number, since it is smaller than the sum of its proper divisors (595910400).

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

216686400 is a wasteful number, since it uses less digits than its factorization.

216686400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6481 (or 6466 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 216686400 is about 14720.2717366223. The cubic root of 216686400 is about 600.6348835235.

It can be divided in two parts, 2166 and 86400, that multiplied together give a square (187142400 = 13680²).

The spelling of 216686400 in words is "two hundred sixteen million, six hundred eighty-six thousand, four hundred".