66147815868 has 12 divisors (see below), whose sum is σ = 154344903720. Its totient is φ = 22049271952.

The previous prime is 66147815863. The next prime is 66147815879. The reversal of 66147815868 is 86851874166.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66147815863) 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, 2756158983 + ... + 2756159006.

It is an arithmetic number, because the mean of its divisors is an integer number (12862075310).

Almost surely, 2^66147815868 is an apocalyptic number.

It is an amenable number.

66147815868 is an abundant number, since it is smaller than the sum of its proper divisors (88197087852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66147815868 is a wasteful number, since it uses less digits than its factorization.

66147815868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5512317996 (or 5512317994 counting only the distinct ones).

The product of its digits is 15482880, while the sum is 60.

The spelling of 66147815868 in words is "sixty-six billion, one hundred forty-seven million, eight hundred fifteen thousand, eight hundred sixty-eight".