79666716517 has 4 divisors (see below), whose sum is σ = 79769779020. Its totient is φ = 79563654016.

The previous prime is 79666716443. The next prime is 79666716523. The reversal of 79666716517 is 71561766697.

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 1292474401 + 78374242116 = 35951^2 + 279954^2 .

It is a cyclic number.

It is not a de Polignac number, because 79666716517 - 2³⁵ = 45306978149 is a prime.

It is a super-2 number, since 2×79666716517² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79666710517) 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 3 ways as a sum of consecutive naturals, for example, 51530092 + ... + 51531637.

It is an arithmetic number, because the mean of its divisors is an integer number (19942444755).

Almost surely, 2^79666716517 is an apocalyptic number.

It is an amenable number.

79666716517 is a deficient number, since it is larger than the sum of its proper divisors (103062503).

79666716517 is a wasteful number, since it uses less digits than its factorization.

79666716517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103062502.

The product of its digits is 20003760, while the sum is 61.

The spelling of 79666716517 in words is "seventy-nine billion, six hundred sixty-six million, seven hundred sixteen thousand, five hundred seventeen".