216905728 has 48 divisors (see below), whose sum is σ = 467124840. Its totient is φ = 100098048.

The previous prime is 216905719. The next prime is 216905783. The reversal of 216905728 is 827509612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22551 + ... + 30697.

Almost surely, 2^216905728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216905728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (233562420).

216905728 is an abundant number, since it is smaller than the sum of its proper divisors (250219112).

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

216905728 is an equidigital number, since it uses as much as digits as its factorization.

216905728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8182 (or 8162 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 216905728 is about 14727.7197148778. The cubic root of 216905728 is about 600.8374675733.

The spelling of 216905728 in words is "two hundred sixteen million, nine hundred five thousand, seven hundred twenty-eight".