664235647 has 4 divisors (see below), whose sum is σ = 664292160. Its totient is φ = 664179136.

The previous prime is 664235641. The next prime is 664235651. The reversal of 664235647 is 746532466.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 664235647 - 2³ = 664235639 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 (664235641) 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, 3247 + ... + 36592.

It is an arithmetic number, because the mean of its divisors is an integer number (166073040).

Almost surely, 2^664235647 is an apocalyptic number.

664235647 is a deficient number, since it is larger than the sum of its proper divisors (56513).

664235647 is a wasteful number, since it uses less digits than its factorization.

664235647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56512.

The product of its digits is 725760, while the sum is 43.

The square root of 664235647 is about 25772.7694864172. The cubic root of 664235647 is about 872.5173257863.

The spelling of 664235647 in words is "six hundred sixty-four million, two hundred thirty-five thousand, six hundred forty-seven".