664147257 has 4 divisors (see below), whose sum is σ = 885529680. Its totient is φ = 442764836.

The previous prime is 664147207. The next prime is 664147259. The reversal of 664147257 is 752741466.

664147257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 664147257 - 2¹⁸ = 663885113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (664147259) 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, 110691207 + ... + 110691212.

It is an arithmetic number, because the mean of its divisors is an integer number (221382420).

Almost surely, 2^664147257 is an apocalyptic number.

It is an amenable number.

664147257 is a deficient number, since it is larger than the sum of its proper divisors (221382423).

664147257 is a wasteful number, since it uses less digits than its factorization.

664147257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221382422.

The product of its digits is 282240, while the sum is 42.

The square root of 664147257 is about 25771.0546349970. The cubic root of 664147257 is about 872.4786220381.

The spelling of 664147257 in words is "six hundred sixty-four million, one hundred forty-seven thousand, two hundred fifty-seven".