664993720597 has 4 divisors (see below), whose sum is σ = 665167216140. Its totient is φ = 664820225056.

The previous prime is 664993720553. The next prime is 664993720631. The reversal of 664993720597 is 795027399466.

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

It can be written as a sum of positive squares in 2 ways, for example, as 400791552561 + 264202168036 = 633081^2 + 514006^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-664993720597 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 (664993720297) 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, 86742022 + ... + 86749687.

It is an arithmetic number, because the mean of its divisors is an integer number (166291804035).

Almost surely, 2^664993720597 is an apocalyptic number.

It is an amenable number.

664993720597 is a deficient number, since it is larger than the sum of its proper divisors (173495543).

664993720597 is a wasteful number, since it uses less digits than its factorization.

664993720597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173495542.

The product of its (nonzero) digits is 154314720, while the sum is 67.

The spelling of 664993720597 in words is "six hundred sixty-four billion, nine hundred ninety-three million, seven hundred twenty thousand, five hundred ninety-seven".