66307889664 has 60 divisors (see below), whose sum is σ = 191369072466. Its totient is φ = 22102628352.

The previous prime is 66307889633. The next prime is 66307889677. The reversal of 66307889664 is 46698870366.

It can be written as a sum of positive squares in only one way, i.e., 64353542400 + 1954347264 = 253680^2 + 44208^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7190259 + ... + 7199474.

Almost surely, 2^66307889664 is an apocalyptic number.

66307889664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66307889664 is an abundant number, since it is smaller than the sum of its proper divisors (125061182802).

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

66307889664 is a wasteful number, since it uses less digits than its factorization.

66307889664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14389757 (or 14389738 counting only the distinct ones).

The product of its (nonzero) digits is 62705664, while the sum is 63.

The spelling of 66307889664 in words is "sixty-six billion, three hundred seven million, eight hundred eighty-nine thousand, six hundred sixty-four".