640328386 has 16 divisors (see below), whose sum is σ = 1011636000. Its totient is φ = 303136128.

The previous prime is 640328383. The next prime is 640328411. The reversal of 640328386 is 683823046.

It is not an unprimeable number, because it can be changed into a prime (640328383) 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, 79890 + ... + 87538.

It is an arithmetic number, because the mean of its divisors is an integer number (63227250).

Almost surely, 2^640328386 is an apocalyptic number.

640328386 is a deficient number, since it is larger than the sum of its proper divisors (371307614).

640328386 is a wasteful number, since it uses less digits than its factorization.

640328386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9873.

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 640328386 is about 25304.7107472107. The cubic root of 640328386 is about 861.9212437670.

The spelling of 640328386 in words is "six hundred forty million, three hundred twenty-eight thousand, three hundred eighty-six".