66005664 has 24 divisors (see below), whose sum is σ = 173265120. Its totient is φ = 22001856.

The previous prime is 66005663. The next prime is 66005683. The reversal of 66005664 is 46650066.

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (66005663) 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, 343684 + ... + 343875.

It is an arithmetic number, because the mean of its divisors is an integer number (7219380).

Almost surely, 2^66005664 is an apocalyptic number.

It is an amenable number.

66005664 is an abundant number, since it is smaller than the sum of its proper divisors (107259456).

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

66005664 is a wasteful number, since it uses less digits than its factorization.

66005664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 687572 (or 687564 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 33.

The square root of 66005664 is about 8124.3869922598. The cubic root of 66005664 is about 404.1355621272.

The spelling of 66005664 in words is "sixty-six million, five thousand, six hundred sixty-four".