66645906164 has 12 divisors (see below), whose sum is σ = 116745476484. Its totient is φ = 33290055744.

The previous prime is 66645906137. The next prime is 66645906211. The reversal of 66645906164 is 46160954666.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16965062500 + 49680843664 = 130250^2 + 222892^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8219777 + ... + 8227880.

It is an arithmetic number, because the mean of its divisors is an integer number (9728789707).

Almost surely, 2^66645906164 is an apocalyptic number.

It is an amenable number.

66645906164 is a deficient number, since it is larger than the sum of its proper divisors (50099570320).

66645906164 is a wasteful number, since it uses less digits than its factorization.

66645906164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16448674 (or 16448672 counting only the distinct ones).

The product of its (nonzero) digits is 5598720, while the sum is 53.

The spelling of 66645906164 in words is "sixty-six billion, six hundred forty-five million, nine hundred six thousand, one hundred sixty-four".