640043358694 has 32 divisors (see below), whose sum is σ = 984662148096. Its totient is φ = 311881656000.

The previous prime is 640043358679. The next prime is 640043358709. The reversal of 640043358694 is 496853340046.

It is an interprime number because it is at equal distance from previous prime (640043358679) and next prime (640043358709).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 74186409 + ... + 74195035.

It is an arithmetic number, because the mean of its divisors is an integer number (30770692128).

Almost surely, 2^640043358694 is an apocalyptic number.

640043358694 is a deficient number, since it is larger than the sum of its proper divisors (344618789402).

640043358694 is a wasteful number, since it uses less digits than its factorization.

640043358694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11940.

The product of its (nonzero) digits is 7464960, while the sum is 52.

The spelling of 640043358694 in words is "six hundred forty billion, forty-three million, three hundred fifty-eight thousand, six hundred ninety-four".