2668743821 has 18 divisors (see below), whose sum is σ = 2829474270. Its totient is φ = 2514133440.

The previous prime is 2668743809. The next prime is 2668743877. The reversal of 2668743821 is 1283478662.

2668743821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 9 ways, for example, as 1458399721 + 1210344100 = 38189^2 + 34790^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2668743821 is a prime.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2668748821) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 14744351 + ... + 14744531.

It is an arithmetic number, because the mean of its divisors is an integer number (157193015).

Almost surely, 2^2668743821 is an apocalyptic number.

It is an amenable number.

2668743821 is a deficient number, since it is larger than the sum of its proper divisors (160730449).

2668743821 is an frugal number, since it uses more digits than its factorization.

2668743821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497 (or 263 counting only the distinct ones).

The product of its digits is 774144, while the sum is 47.

The square root of 2668743821 is about 51659.8859948413. The cubic root of 2668743821 is about 1387.0825098495.

The spelling of 2668743821 in words is "two billion, six hundred sixty-eight million, seven hundred forty-three thousand, eight hundred twenty-one".