66165664 has 24 divisors (see below), whose sum is σ = 135928800. Its totient is φ = 31644096.

The previous prime is 66165653. The next prime is 66165679. The reversal of 66165664 is 46656166.

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, 44214 + ... + 45685.

It is an arithmetic number, because the mean of its divisors is an integer number (5663700).

Almost surely, 2^66165664 is an apocalyptic number.

It is an amenable number.

66165664 is an abundant number, since it is smaller than the sum of its proper divisors (69763136).

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

66165664 is a wasteful number, since it uses less digits than its factorization.

66165664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89932 (or 89924 counting only the distinct ones).

The product of its digits is 155520, while the sum is 40.

The square root of 66165664 is about 8134.2279289432. The cubic root of 66165664 is about 404.4618447970.

The spelling of 66165664 in words is "sixty-six million, one hundred sixty-five thousand, six hundred sixty-four".