1664325317 has 4 divisors (see below), whose sum is σ = 1664721996. Its totient is φ = 1663928640.

The previous prime is 1664325307. The next prime is 1664325323. The reversal of 1664325317 is 7135234661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7135234661 = 4201 ⋅1698461.

It can be written as a sum of positive squares in 2 ways, for example, as 1429898596 + 234426721 = 37814^2 + 15311^2 .

It is a cyclic number.

It is not a de Polignac number, because 1664325317 - 2⁴ = 1664325301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664325307) 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, 191978 + ... + 200459.

It is an arithmetic number, because the mean of its divisors is an integer number (416180499).

Almost surely, 2^1664325317 is an apocalyptic number.

It is an amenable number.

1664325317 is a deficient number, since it is larger than the sum of its proper divisors (396679).

1664325317 is an equidigital number, since it uses as much as digits as its factorization.

1664325317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396678.

The product of its digits is 90720, while the sum is 38.

The square root of 1664325317 is about 40796.1434084155. The cubic root of 1664325317 is about 1185.0756459154.

Adding to 1664325317 its reverse (7135234661), we get a palindrome (8799559978).

The spelling of 1664325317 in words is "one billion, six hundred sixty-four million, three hundred twenty-five thousand, three hundred seventeen".