7991677521 has 12 divisors (see below), whose sum is σ = 11556559872. Its totient is φ = 5321773176.

The previous prime is 7991677513. The next prime is 7991677531. The reversal of 7991677521 is 1257761997.

It is a happy number.

It is not a de Polignac number, because 7991677521 - 2³ = 7991677513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (7991677531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 492561 + ... + 508526.

It is an arithmetic number, because the mean of its divisors is an integer number (963046656).

Almost surely, 2^7991677521 is an apocalyptic number.

It is an amenable number.

7991677521 is a deficient number, since it is larger than the sum of its proper divisors (3564882351).

7991677521 is a wasteful number, since it uses less digits than its factorization.

7991677521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1001980 (or 1001977 counting only the distinct ones).

The product of its digits is 1666980, while the sum is 54.

The square root of 7991677521 is about 89396.1829218675. The cubic root of 7991677521 is about 1999.3062194454.

The spelling of 7991677521 in words is "seven billion, nine hundred ninety-one million, six hundred seventy-seven thousand, five hundred twenty-one".