2851721845 has 12 divisors (see below), whose sum is σ = 3980771244. Its totient is φ = 1955466240.

The previous prime is 2851721833. The next prime is 2851721849. The reversal of 2851721845 is 5481271582.

It can be written as a sum of positive squares in 2 ways, for example, as 438357969 + 2413363876 = 20937^2 + 49126^2 .

It is not a de Polignac number, because 2851721845 - 2¹¹ = 2851719797 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 (2851721849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5819596 + ... + 5820085.

It is an arithmetic number, because the mean of its divisors is an integer number (331730937).

Almost surely, 2^2851721845 is an apocalyptic number.

It is an amenable number.

2851721845 is a deficient number, since it is larger than the sum of its proper divisors (1129049399).

2851721845 is a wasteful number, since it uses less digits than its factorization.

2851721845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11639700 (or 11639693 counting only the distinct ones).

The product of its digits is 179200, while the sum is 43.

The square root of 2851721845 is about 53401.5153811200. The cubic root of 2851721845 is about 1418.0854057162.

The spelling of 2851721845 in words is "two billion, eight hundred fifty-one million, seven hundred twenty-one thousand, eight hundred forty-five".