640218374 has 8 divisors (see below), whose sum is σ = 960818760. Its totient is φ = 319945456.

The previous prime is 640218361. The next prime is 640218377. The reversal of 640218374 is 473812046.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640218377) 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 3 ways as a sum of consecutive naturals, for example, 76919 + ... + 84834.

It is an arithmetic number, because the mean of its divisors is an integer number (120102345).

Almost surely, 2^640218374 is an apocalyptic number.

640218374 is a deficient number, since it is larger than the sum of its proper divisors (320600386).

640218374 is a wasteful number, since it uses less digits than its factorization.

640218374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163734.

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 640218374 is about 25302.5369083813. The cubic root of 640218374 is about 861.8718799755.

The spelling of 640218374 in words is "six hundred forty million, two hundred eighteen thousand, three hundred seventy-four".