165664566 has 48 divisors (see below), whose sum is σ = 372902400. Its totient is φ = 53114544.

The previous prime is 165664547. The next prime is 165664567. The reversal of 165664566 is 665466561.

165664566 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165664567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48255 + ... + 51573.

It is an arithmetic number, because the mean of its divisors is an integer number (7768800).

Almost surely, 2^165664566 is an apocalyptic number.

165664566 is an abundant number, since it is smaller than the sum of its proper divisors (207237834).

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

165664566 is a wasteful number, since it uses less digits than its factorization.

165664566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3433 (or 3430 counting only the distinct ones).

The product of its digits is 777600, while the sum is 45.

The square root of 165664566 is about 12871.0747802971. The cubic root of 165664566 is about 549.2160356934.

The spelling of 165664566 in words is "one hundred sixty-five million, six hundred sixty-four thousand, five hundred sixty-six".