2128807321 has 27 divisors (see below), whose sum is σ = 2319865821. Its totient is φ = 1953340704.

The previous prime is 2128807313. The next prime is 2128807349. The reversal of 2128807321 is 1237088212.

The square root of 2128807321 is 46139.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 453051225 + 1675756096 = 21285^2 + 40936^2 .

It is not a de Polignac number, because 2128807321 - 2³ = 2128807313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2128807621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 49507126 + ... + 49507168.

Almost surely, 2^2128807321 is an apocalyptic number.

2128807321 is the 46139-th square number.

2128807321 is the 23070-th centered octagonal number.

It is an amenable number.

2128807321 is a deficient number, since it is larger than the sum of its proper divisors (191058500).

2128807321 is an frugal number, since it uses more digits than its factorization.

2128807321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The cubic root of 2128807321 is about 1286.4081563912.

The spelling of 2128807321 in words is "two billion, one hundred twenty-eight million, eight hundred seven thousand, three hundred twenty-one".