79687079521 has 21 divisors (see below), whose sum is σ = 93081246321. Its totient is φ = 68220218052.

The previous prime is 79687079503. The next prime is 79687079567. The reversal of 79687079521 is 12597078697.

The square root of 79687079521 is 282289.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 79687079521 - 2⁷ = 79687079393 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 79687079521.

It is not an unprimeable number, because it can be changed into a prime (79687079501) 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 20 ways as a sum of consecutive naturals, for example, 96824716 + ... + 96825538.

It is an arithmetic number, because the mean of its divisors is an integer number (4432440301).

Almost surely, 2^79687079521 is an apocalyptic number.

79687079521 is the 282289-th square number.

79687079521 is the 141145-th centered octagonal number.

It is an amenable number.

79687079521 is a deficient number, since it is larger than the sum of its proper divisors (13394166800).

79687079521 is an frugal number, since it uses more digits than its factorization.

79687079521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1688 (or 830 counting only the distinct ones).

The product of its (nonzero) digits is 13335840, while the sum is 61.

The spelling of 79687079521 in words is "seventy-nine billion, six hundred eighty-seven million, seventy-nine thousand, five hundred twenty-one".