640397185 has 8 divisors (see below), whose sum is σ = 808922880. Its totient is φ = 485353584.

The previous prime is 640397179. The next prime is 640397203. The reversal of 640397185 is 581793046.

640397185 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640397185 - 2⁷ = 640397057 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3370417 + ... + 3370606.

It is an arithmetic number, because the mean of its divisors is an integer number (101115360).

Almost surely, 2^640397185 is an apocalyptic number.

It is an amenable number.

640397185 is a deficient number, since it is larger than the sum of its proper divisors (168525695).

640397185 is a wasteful number, since it uses less digits than its factorization.

640397185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6741047.

The product of its (nonzero) digits is 181440, while the sum is 43.

The square root of 640397185 is about 25306.0701216131. The cubic root of 640397185 is about 861.9521118847.

The spelling of 640397185 in words is "six hundred forty million, three hundred ninety-seven thousand, one hundred eighty-five".