2165228728 has 64 divisors (see below), whose sum is σ = 4590028800. Its totient is φ = 950624640.

The previous prime is 2165228701. The next prime is 2165228731. The reversal of 2165228728 is 8278225612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 184525 + ... + 195907.

It is an arithmetic number, because the mean of its divisors is an integer number (71719200).

Almost surely, 2^2165228728 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 2165228728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2295014400).

2165228728 is an abundant number, since it is smaller than the sum of its proper divisors (2424800072).

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

2165228728 is a wasteful number, since it uses less digits than its factorization.

2165228728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11492 (or 11488 counting only the distinct ones).

The product of its digits is 215040, while the sum is 43.

The square root of 2165228728 is about 46532.0183099766. The cubic root of 2165228728 is about 1293.7030247112.

The spelling of 2165228728 in words is "two billion, one hundred sixty-five million, two hundred twenty-eight thousand, seven hundred twenty-eight".