7921577871 has 16 divisors (see below), whose sum is σ = 11739297120. Its totient is φ = 5279420160.

The previous prime is 7921577857. The next prime is 7921577903. The reversal of 7921577871 is 1787751297.

7921577871 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-7921577871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7921577801) 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 15 ways as a sum of consecutive naturals, for example, 47101 + ... + 134393.

It is an arithmetic number, because the mean of its divisors is an integer number (733706070).

Almost surely, 2^7921577871 is an apocalyptic number.

7921577871 is a deficient number, since it is larger than the sum of its proper divisors (3817719249).

7921577871 is a wasteful number, since it uses less digits than its factorization.

7921577871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90663 (or 90657 counting only the distinct ones).

The product of its digits is 1728720, while the sum is 54.

The square root of 7921577871 is about 89003.2464070834. The cubic root of 7921577871 is about 1993.4433512509.

The spelling of 7921577871 in words is "seven billion, nine hundred twenty-one million, five hundred seventy-seven thousand, eight hundred seventy-one".