79911112021 has 4 divisors (see below), whose sum is σ = 86058120652. Its totient is φ = 73764103392.

The previous prime is 79911111997. The next prime is 79911112037. The reversal of 79911112021 is 12021111997.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 48622455025 + 31288656996 = 220505^2 + 176886^2 .

It is a cyclic number.

It is not a de Polignac number, because 79911112021 - 2¹³ = 79911103829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79911112921) 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, 3073504296 + ... + 3073504321.

It is an arithmetic number, because the mean of its divisors is an integer number (21514530163).

Almost surely, 2^79911112021 is an apocalyptic number.

It is an amenable number.

79911112021 is a deficient number, since it is larger than the sum of its proper divisors (6147008631).

79911112021 is a wasteful number, since it uses less digits than its factorization.

79911112021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6147008630.

The product of its (nonzero) digits is 2268, while the sum is 34.

The spelling of 79911112021 in words is "seventy-nine billion, nine hundred eleven million, one hundred twelve thousand, twenty-one".