66489361585 has 4 divisors (see below), whose sum is σ = 79787233908. Its totient is φ = 53191489264.

The previous prime is 66489361583. The next prime is 66489361591. The reversal of 66489361585 is 58516398466.

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 28975869729 + 37513491856 = 170223^2 + 193684^2 .

It is a cyclic number.

It is not a de Polignac number, because 66489361585 - 2¹ = 66489361583 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66489361583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6648936154 + ... + 6648936163.

It is an arithmetic number, because the mean of its divisors is an integer number (19946808477).

Almost surely, 2^66489361585 is an apocalyptic number.

It is an amenable number.

66489361585 is a deficient number, since it is larger than the sum of its proper divisors (13297872323).

66489361585 is a wasteful number, since it uses less digits than its factorization.

66489361585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13297872322.

The product of its digits is 37324800, while the sum is 61.

The spelling of 66489361585 in words is "sixty-six billion, four hundred eighty-nine million, three hundred sixty-one thousand, five hundred eighty-five".