664435321 has 12 divisors (see below), whose sum is σ = 730982896. Its totient is φ = 603492120.

The previous prime is 664435319. The next prime is 664435337. The reversal of 664435321 is 123534466.

It is not a de Polignac number, because 664435321 - 2¹ = 664435319 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664435351) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 206890 + ... + 210076.

Almost surely, 2^664435321 is an apocalyptic number.

It is an amenable number.

664435321 is a deficient number, since it is larger than the sum of its proper divisors (66547575).

664435321 is a wasteful number, since it uses less digits than its factorization.

664435321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4932 (or 4921 counting only the distinct ones).

The product of its digits is 51840, while the sum is 34.

The square root of 664435321 is about 25776.6429350294. The cubic root of 664435321 is about 872.6047453494.

Adding to 664435321 its reverse (123534466), we get a palindrome (787969787).

The spelling of 664435321 in words is "six hundred sixty-four million, four hundred thirty-five thousand, three hundred twenty-one".