664571840 has 56 divisors (see below), whose sum is σ = 1584911232. Its totient is φ = 265425920.

The previous prime is 664571827. The next prime is 664571849. The reversal of 664571840 is 48175466.

664571840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664571849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 300017 + ... + 302223.

Almost surely, 2^664571840 is an apocalyptic number.

It is an amenable number.

664571840 is an abundant number, since it is smaller than the sum of its proper divisors (920339392).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664571840 is a wasteful number, since it uses less digits than its factorization.

664571840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3165 (or 3155 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 41.

The square root of 664571840 is about 25779.2909134445. The cubic root of 664571840 is about 872.6645048502.

The spelling of 664571840 in words is "six hundred sixty-four million, five hundred seventy-one thousand, eight hundred forty".