664445023 has 4 divisors (see below), whose sum is σ = 724849128. Its totient is φ = 604040920.

The previous prime is 664445021. The next prime is 664445083. The reversal of 664445023 is 320544466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 664445023 - 2¹ = 664445021 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 664445023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664445021) 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, 30202036 + ... + 30202057.

It is an arithmetic number, because the mean of its divisors is an integer number (181212282).

Almost surely, 2^664445023 is an apocalyptic number.

664445023 is a deficient number, since it is larger than the sum of its proper divisors (60404105).

664445023 is a wasteful number, since it uses less digits than its factorization.

664445023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60404104.

The product of its (nonzero) digits is 69120, while the sum is 34.

The square root of 664445023 is about 25776.8311279723. The cubic root of 664445023 is about 872.6089925499.

Adding to 664445023 its reverse (320544466), we get a palindrome (984989489).

The spelling of 664445023 in words is "six hundred sixty-four million, four hundred forty-five thousand, twenty-three".