79007971721 has 4 divisors (see below), whose sum is σ = 90294824832. Its totient is φ = 67721118612.

The previous prime is 79007971687. The next prime is 79007971723. The reversal of 79007971721 is 12717970097.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 79007971721 - 2³⁴ = 61828102537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 79007971721.

It is not an unprimeable number, because it can be changed into a prime (79007971723) 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, 5643426545 + ... + 5643426558.

It is an arithmetic number, because the mean of its divisors is an integer number (22573706208).

Almost surely, 2^79007971721 is an apocalyptic number.

It is an amenable number.

79007971721 is a deficient number, since it is larger than the sum of its proper divisors (11286853111).

79007971721 is a wasteful number, since it uses less digits than its factorization.

79007971721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11286853110.

The product of its (nonzero) digits is 388962, while the sum is 50.

The spelling of 79007971721 in words is "seventy-nine billion, seven million, nine hundred seventy-one thousand, seven hundred twenty-one".