216440320 has 80 divisors (see below), whose sum is σ = 528113520. Its totient is φ = 85049344.

The previous prime is 216440317. The next prime is 216440339. The reversal of 216440320 is 23044612.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 216440291 and 216440300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150324 + ... + 151756.

It is an arithmetic number, because the mean of its divisors is an integer number (6601419).

Almost surely, 2^216440320 is an apocalyptic number.

216440320 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 216440320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (264056760).

216440320 is an abundant number, since it is smaller than the sum of its proper divisors (311673200).

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

216440320 is an equidigital number, since it uses as much as digits as its factorization.

216440320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1515 (or 1499 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 216440320 is about 14711.9108208281. The cubic root of 216440320 is about 600.4074269798.

Adding to 216440320 its reverse (23044612), we get a palindrome (239484932).

The spelling of 216440320 in words is "two hundred sixteen million, four hundred forty thousand, three hundred twenty".