664688512513 has 2 divisors, whose sum is σ = 664688512514. Its totient is φ = 664688512512.

The previous prime is 664688512507. The next prime is 664688512531. The reversal of 664688512513 is 315215886466.

Together with next prime (664688512531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 663527543184 + 1160969329 = 814572^2 + 34073^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664688512513 is a prime.

It is not a weakly prime, because it can be changed into another prime (664688512583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332344256256 + 332344256257.

It is an arithmetic number, because the mean of its divisors is an integer number (332344256257).

Almost surely, 2^664688512513 is an apocalyptic number.

It is an amenable number.

664688512513 is a deficient number, since it is larger than the sum of its proper divisors (1).

664688512513 is an equidigital number, since it uses as much as digits as its factorization.

664688512513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8294400, while the sum is 55.

The spelling of 664688512513 in words is "six hundred sixty-four billion, six hundred eighty-eight million, five hundred twelve thousand, five hundred thirteen".