7928491887 has 12 divisors (see below), whose sum is σ = 11461153704. Its totient is φ = 5281559280.

The previous prime is 7928491877. The next prime is 7928491889. The reversal of 7928491887 is 7881948297.

7928491887 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7928491887 - 2²⁰ = 7927443311 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7928491889) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 329568 + ... + 352805.

It is an arithmetic number, because the mean of its divisors is an integer number (955096142).

Almost surely, 2^7928491887 is an apocalyptic number.

7928491887 is a deficient number, since it is larger than the sum of its proper divisors (3532661817).

7928491887 is a wasteful number, since it uses less digits than its factorization.

7928491887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683670 (or 683667 counting only the distinct ones).

The product of its digits is 16257024, while the sum is 63.

The square root of 7928491887 is about 89042.0793052364. The cubic root of 7928491887 is about 1994.0231469899.

It can be divided in two parts, 79284 and 91887, that added together give a palindrome (171171).

The spelling of 7928491887 in words is "seven billion, nine hundred twenty-eight million, four hundred ninety-one thousand, eight hundred eighty-seven".