86638155815557 has 4 divisors (see below), whose sum is σ = 86638194623596. Its totient is φ = 86638117007520.

The previous prime is 86638155815531. The next prime is 86638155815573. The reversal of 86638155815557 is 75551855183668.

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 17409998255841 + 69228157559716 = 4172529^2 + 8320346^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-86638155815557 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 86638155815557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86638155815507) 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, 15836688 + ... + 20593129.

It is an arithmetic number, because the mean of its divisors is an integer number (21659548655899).

Almost surely, 2^{86638155815557} is an apocalyptic number.

It is an amenable number.

86638155815557 is a deficient number, since it is larger than the sum of its proper divisors (38808039).

86638155815557 is a wasteful number, since it uses less digits than its factorization.

86638155815557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38808038.

The product of its digits is 1209600000, while the sum is 73.

The spelling of 86638155815557 in words is "eighty-six trillion, six hundred thirty-eight billion, one hundred fifty-five million, eight hundred fifteen thousand, five hundred fifty-seven".