640043358765 has 16 divisors (see below), whose sum is σ = 1028464527168. Its totient is φ = 339891406976.

The previous prime is 640043358733. The next prime is 640043358767. The reversal of 640043358765 is 567853340046.

It is a cyclic number.

It is not a de Polignac number, because 640043358765 - 2⁵ = 640043358733 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640043358767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91562079 + ... + 91569068.

It is an arithmetic number, because the mean of its divisors is an integer number (64279032948).

Almost surely, 2^640043358765 is an apocalyptic number.

It is an amenable number.

640043358765 is a deficient number, since it is larger than the sum of its proper divisors (388421168403).

640043358765 is a wasteful number, since it uses less digits than its factorization.

640043358765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183131388.

The product of its (nonzero) digits is 7257600, while the sum is 51.

The spelling of 640043358765 in words is "six hundred forty billion, forty-three million, three hundred fifty-eight thousand, seven hundred sixty-five".