79909769081 has 4 divisors (see below), whose sum is σ = 79910421492. Its totient is φ = 79909116672.

The previous prime is 79909769057. The next prime is 79909769111. The reversal of 79909769081 is 18096790997.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 18096790997 = 4133 ⋅4378609.

It can be written as a sum of positive squares in 2 ways, for example, as 11169319225 + 68740449856 = 105685^2 + 262184^2 .

It is a cyclic number.

It is not a de Polignac number, because 79909769081 - 2²⁶ = 79842660217 is a prime.

It is a super-2 number, since 2×79909769081² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 79909768999 and 79909769017.

It is not an unprimeable number, because it can be changed into a prime (79909762081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81080 + ... + 407913.

It is an arithmetic number, because the mean of its divisors is an integer number (19977605373).

Almost surely, 2^79909769081 is an apocalyptic number.

It is an amenable number.

79909769081 is a deficient number, since it is larger than the sum of its proper divisors (652411).

79909769081 is a wasteful number, since it uses less digits than its factorization.

79909769081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 652410.

The product of its (nonzero) digits is 15431472, while the sum is 65.

The spelling of 79909769081 in words is "seventy-nine billion, nine hundred nine million, seven hundred sixty-nine thousand, eighty-one".