664308891 has 16 divisors (see below), whose sum is σ = 987095200. Its totient is φ = 441552384.

The previous prime is 664308859. The next prime is 664308923. The reversal of 664308891 is 198803466.

664308891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (664308859) and next prime (664308923).

It is not a de Polignac number, because 664308891 - 2⁵ = 664308859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664308811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27406 + ... + 45603.

It is an arithmetic number, because the mean of its divisors is an integer number (61693450).

Almost surely, 2^664308891 is an apocalyptic number.

664308891 is a deficient number, since it is larger than the sum of its proper divisors (322786309).

664308891 is a wasteful number, since it uses less digits than its factorization.

664308891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73355 (or 73349 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 45.

The square root of 664308891 is about 25774.1904043561. The cubic root of 664308891 is about 872.5493948823.

The spelling of 664308891 in words is "six hundred sixty-four million, three hundred eight thousand, eight hundred ninety-one".