66645305664 has 112 divisors (see below), whose sum is σ = 201670115328. Its totient is φ = 19027588608.

The previous prime is 66645305653. The next prime is 66645305677. The reversal of 66645305664 is 46650354666.

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1895089 + ... + 1929935.

Almost surely, 2^66645305664 is an apocalyptic number.

66645305664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66645305664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100835057664).

66645305664 is an abundant number, since it is smaller than the sum of its proper divisors (135024809664).

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

66645305664 is a wasteful number, since it uses less digits than its factorization.

66645305664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36292 (or 36282 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 51.

The spelling of 66645305664 in words is "sixty-six billion, six hundred forty-five million, three hundred five thousand, six hundred sixty-four".