640964418 has 16 divisors (see below), whose sum is σ = 1284395616. Its totient is φ = 213243680.

The previous prime is 640964417. The next prime is 640964459. The reversal of 640964418 is 814469046.

It is a self number, because there is not a number n which added to its sum of digits gives 640964418.

It is not an unprimeable number, because it can be changed into a prime (640964417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99396 + ... + 105647.

It is an arithmetic number, because the mean of its divisors is an integer number (80274726).

Almost surely, 2^640964418 is an apocalyptic number.

640964418 is an abundant number, since it is smaller than the sum of its proper divisors (643431198).

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

640964418 is a wasteful number, since it uses less digits than its factorization.

640964418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205569.

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 640964418 is about 25317.2750903410. The cubic root of 640964418 is about 862.2065286792.

The spelling of 640964418 in words is "six hundred forty million, nine hundred sixty-four thousand, four hundred eighteen".