2720821855 has 4 divisors (see below), whose sum is σ = 3264986232. Its totient is φ = 2176657480.

The previous prime is 2720821853. The next prime is 2720821871. The reversal of 2720821855 is 5581280272.

2720821855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 2720821855 - 2¹ = 2720821853 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2720821853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272082181 + ... + 272082190.

It is an arithmetic number, because the mean of its divisors is an integer number (816246558).

Almost surely, 2^2720821855 is an apocalyptic number.

2720821855 is a deficient number, since it is larger than the sum of its proper divisors (544164377).

2720821855 is an equidigital number, since it uses as much as digits as its factorization.

2720821855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544164376.

The product of its (nonzero) digits is 89600, while the sum is 40.

The square root of 2720821855 is about 52161.4978216692. The cubic root of 2720821855 is about 1396.0469874621.

The spelling of 2720821855 in words is "two billion, seven hundred twenty million, eight hundred twenty-one thousand, eight hundred fifty-five".