79521681571 has 4 divisors (see below), whose sum is σ = 80147836672. Its totient is φ = 78895526472.

The previous prime is 79521681563. The next prime is 79521681581. The reversal of 79521681571 is 17518612597.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17518612597 = 2857 ⋅6131821.

It is a cyclic number.

It is not a de Polignac number, because 79521681571 - 2³ = 79521681563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79521681511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313077360 + ... + 313077613.

It is an arithmetic number, because the mean of its divisors is an integer number (20036959168).

Almost surely, 2^79521681571 is an apocalyptic number.

79521681571 is a deficient number, since it is larger than the sum of its proper divisors (626155101).

79521681571 is a wasteful number, since it uses less digits than its factorization.

79521681571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626155100.

The product of its digits is 1058400, while the sum is 52.

The spelling of 79521681571 in words is "seventy-nine billion, five hundred twenty-one million, six hundred eighty-one thousand, five hundred seventy-one".