664806893 has 6 divisors (see below), whose sum is σ = 666485514. Its totient is φ = 663130944.

The previous prime is 664806889. The next prime is 664806899. The reversal of 664806893 is 398608466.

664806893 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 1898884 + 662908009 = 1378^2 + 25747^2 .

It is not a de Polignac number, because 664806893 - 2² = 664806889 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 (664806899) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 658373 + ... + 659381.

It is an arithmetic number, because the mean of its divisors is an integer number (111080919).

Almost surely, 2^664806893 is an apocalyptic number.

It is an amenable number.

664806893 is a deficient number, since it is larger than the sum of its proper divisors (1678621).

664806893 is an frugal number, since it uses more digits than its factorization.

664806893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2671 (or 1662 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 50.

The square root of 664806893 is about 25783.8494604665. The cubic root of 664806893 is about 872.7673772155.

The spelling of 664806893 in words is "six hundred sixty-four million, eight hundred six thousand, eight hundred ninety-three".