2728385221 has 8 divisors (see below), whose sum is σ = 2891309400. Its totient is φ = 2570050560.

The previous prime is 2728385201. The next prime is 2728385263. The reversal of 2728385221 is 1225838272.

It can be written as a sum of positive squares in 4 ways, for example, as 29582721 + 2698802500 = 5439^2 + 51950^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2728385221 - 2²⁹ = 2191514309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2728385201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1146156 + ... + 1148533.

It is an arithmetic number, because the mean of its divisors is an integer number (361413675).

Almost surely, 2^2728385221 is an apocalyptic number.

It is an amenable number.

2728385221 is a deficient number, since it is larger than the sum of its proper divisors (162924179).

2728385221 is a wasteful number, since it uses less digits than its factorization.

2728385221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2294759.

The product of its digits is 107520, while the sum is 40.

The square root of 2728385221 is about 52233.9470172416. The cubic root of 2728385221 is about 1397.3393721572.

The spelling of 2728385221 in words is "two billion, seven hundred twenty-eight million, three hundred eighty-five thousand, two hundred twenty-one".