664315609 has 2 divisors, whose sum is σ = 664315610. Its totient is φ = 664315608.

The previous prime is 664315543. The next prime is 664315657. The reversal of 664315609 is 906513466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 659462400 + 4853209 = 25680^2 + 2203^2 .

It is a cyclic number.

It is not a de Polignac number, because 664315609 - 2⁹ = 664315097 is a prime.

It is a super-2 number, since 2×664315609² = 882630456722081762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (664315009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332157804 + 332157805.

It is an arithmetic number, because the mean of its divisors is an integer number (332157805).

Almost surely, 2^664315609 is an apocalyptic number.

It is an amenable number.

664315609 is a deficient number, since it is larger than the sum of its proper divisors (1).

664315609 is an equidigital number, since it uses as much as digits as its factorization.

664315609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 664315609 is about 25774.3207281977. The cubic root of 664315609 is about 872.5523361682.

The spelling of 664315609 in words is "six hundred sixty-four million, three hundred fifteen thousand, six hundred nine".