640018794 has 16 divisors (see below), whose sum is σ = 1309806432. Its totient is φ = 208378128.

The previous prime is 640018793. The next prime is 640018801. The reversal of 640018794 is 497810046.

It is a happy number.

640018794 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (640018793) 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, 1240089 + ... + 1240604.

It is an arithmetic number, because the mean of its divisors is an integer number (81862902).

Almost surely, 2^640018794 is an apocalyptic number.

640018794 is an abundant number, since it is smaller than the sum of its proper divisors (669787638).

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

640018794 is a wasteful number, since it uses less digits than its factorization.

640018794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2480741.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 640018794 is about 25298.5927276598. The cubic root of 640018794 is about 861.7823114397.

The spelling of 640018794 in words is "six hundred forty million, eighteen thousand, seven hundred ninety-four".