2728091821 has 16 divisors (see below), whose sum is σ = 3365712000. Its totient is φ = 2153308608.

The previous prime is 2728091797. The next prime is 2728091827. The reversal of 2728091821 is 1281908272.

It is a cyclic number.

It is not a de Polignac number, because 2728091821 - 2⁵ = 2728091789 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2728091827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2355 + ... + 73903.

It is an arithmetic number, because the mean of its divisors is an integer number (210357000).

Almost surely, 2^2728091821 is an apocalyptic number.

It is an amenable number.

2728091821 is a deficient number, since it is larger than the sum of its proper divisors (637620179).

2728091821 is a wasteful number, since it uses less digits than its factorization.

2728091821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71988.

The product of its (nonzero) digits is 32256, while the sum is 40.

The square root of 2728091821 is about 52231.1384233581. The cubic root of 2728091821 is about 1397.2892822034.

The spelling of 2728091821 in words is "two billion, seven hundred twenty-eight million, ninety-one thousand, eight hundred twenty-one".