216365440 has 64 divisors (see below), whose sum is σ = 528327360. Its totient is φ = 84692992.

The previous prime is 216365423. The next prime is 216365441. The reversal of 216365440 is 44563612.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216365441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26484 + ... + 33676.

It is an arithmetic number, because the mean of its divisors is an integer number (8255115).

Almost surely, 2^216365440 is an apocalyptic number.

216365440 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 216365440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (264163680).

216365440 is an abundant number, since it is smaller than the sum of its proper divisors (311961920).

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

216365440 is an equidigital number, since it uses as much as digits as its factorization.

216365440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7259 (or 7247 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 31.

The square root of 216365440 is about 14709.3657239189. The cubic root of 216365440 is about 600.3381797253.

The spelling of 216365440 in words is "two hundred sixteen million, three hundred sixty-five thousand, four hundred forty".