664731659 has 2 divisors, whose sum is σ = 664731660. Its totient is φ = 664731658.

The previous prime is 664731631. The next prime is 664731673. The reversal of 664731659 is 956137466.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 664731659 - 2¹² = 664727563 is a prime.

It is not a weakly prime, because it can be changed into another prime (664731619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332365829 + 332365830.

It is an arithmetic number, because the mean of its divisors is an integer number (332365830).

Almost surely, 2^664731659 is an apocalyptic number.

664731659 is a deficient number, since it is larger than the sum of its proper divisors (1).

664731659 is an equidigital number, since it uses as much as digits as its factorization.

664731659 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 47.

The square root of 664731659 is about 25782.3904826531. The cubic root of 664731659 is about 872.7344532399.

The spelling of 664731659 in words is "six hundred sixty-four million, seven hundred thirty-one thousand, six hundred fifty-nine".