664340725 has 6 divisors (see below), whose sum is σ = 823782530. Its totient is φ = 531472560.

The previous prime is 664340689. The next prime is 664340741. The reversal of 664340725 is 527043466.

664340725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 69322276 + 595018449 = 8326^2 + 24393^2 .

It is not a de Polignac number, because 664340725 - 2¹¹ = 664338677 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 13286790 + ... + 13286839.

Almost surely, 2^664340725 is an apocalyptic number.

It is an amenable number.

664340725 is a deficient number, since it is larger than the sum of its proper divisors (159441805).

664340725 is a wasteful number, since it uses less digits than its factorization.

664340725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26573639 (or 26573634 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 37.

The square root of 664340725 is about 25774.8079527278. The cubic root of 664340725 is about 872.5633323212.

The spelling of 664340725 in words is "six hundred sixty-four million, three hundred forty thousand, seven hundred twenty-five".