165664689 has 8 divisors (see below), whose sum is σ = 223368480. Its totient is φ = 109202016.

The previous prime is 165664661. The next prime is 165664691. The reversal of 165664689 is 986466561.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165664689 - 2⁵ = 165664657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165664619) 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 7 ways as a sum of consecutive naturals, for example, 309967 + ... + 310500.

It is an arithmetic number, because the mean of its divisors is an integer number (27921060).

Almost surely, 2^165664689 is an apocalyptic number.

It is an amenable number.

165664689 is a deficient number, since it is larger than the sum of its proper divisors (57703791).

165664689 is an equidigital number, since it uses as much as digits as its factorization.

165664689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620559.

The product of its digits is 1866240, while the sum is 51.

The square root of 165664689 is about 12871.0795584520. The cubic root of 165664689 is about 549.2161716178.

The spelling of 165664689 in words is "one hundred sixty-five million, six hundred sixty-four thousand, six hundred eighty-nine".