8128742718517 has 4 divisors (see below), whose sum is σ = 8128757386060. Its totient is φ = 8128728050976.

The previous prime is 8128742718487. The next prime is 8128742718521. The reversal of 8128742718517 is 7158172478218.

It is a happy number.

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 3769224219601 + 4359518498916 = 1941449^2 + 2087946^2 .

It is a cyclic number.

It is not a de Polignac number, because 8128742718517 - 2¹¹ = 8128742716469 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 (8128742718017) 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, 6468438 + ... + 7622215.

It is an arithmetic number, because the mean of its divisors is an integer number (2032189346515).

Almost surely, 2^{8128742718517} is an apocalyptic number.

It is an amenable number.

8128742718517 is a deficient number, since it is larger than the sum of its proper divisors (14667543).

8128742718517 is a wasteful number, since it uses less digits than its factorization.

8128742718517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14667542.

The product of its digits is 14049280, while the sum is 61.

The spelling of 8128742718517 in words is "eight trillion, one hundred twenty-eight billion, seven hundred forty-two million, seven hundred eighteen thousand, five hundred seventeen".